Once again strength in commercial and commercial real estate loans of 5% linked quarters and 15% year over year counted for most of the growth. Quite notably the net interest margin was unchanged at 317. Which speaks to our rigorous pricing discipline. Predicated on relationship profitability and validated by independent outside sources. The strong loan growth and stable nim produced record quarterly net interest income. Night interest income grew 5% link quarter and 4% year over year with particular strength in loan fees. Apart from the 1.8 million year over year decline in mortgage banking revenue, growth was almost 8%. Poor pre-provision net revenue or PPNR grew nearly 3% linked quarter and over 4% year over year to another record. We now report a 21 consecutive quarters of year over year revenue growth dating back to 2009.
Expenses again grew at a lower rate than revenues. Both linked quarter and year over year. Even as we continually invest in our shows and strategies and in risk infrastructure. The net result once again is an efficiency ratio below 16%. Pushing PPNR up 8% linked quarter to another record. The quarter with low loss provision remained in 9.5 million. As loan growth was accompanied by continuing improvement in asset quality. Key quality metric credits are at levels not seen since 2007. Reflecting the improving economy in vigilant mismanagement. We’ve now built reserves in 4 straight quarters totaling about 7 million net add to reserves for the year 2014. Versus a prior year, net release fund reserves of 24 million.
Turning to slide 5, to put performance into full year context, state revenue growth and expense discipline that resulted in record PPNR of 327 million in 2014. Up over 8% from prior year. We’ve now delivered five consecutive years of positive out-bringing leverage. And our full year efficiency ratio has steadily improved over that time by 700 basis points. This performance distinguishes Webster from most of our peers. So, I’ve six demonstrations to balance sheet drivers behind Webster’s multi-year track record and PPNR growth and positive operating leverage. For instance, commercial loans have grown by more than half in 4 years. And now represent 56% of total loans compared to 45% at the end of 2010. Transaction accounts have grown 73% since that time and represent 48% of deposits versus 32% a year in 2010.
The duration of our assets is much shorter than it was prior to the last upgrade cycle 10 years ago. And the duration of our liabilities is longer. So, we’re well positioned for short rate up scenario. I now turn the line to business performance beginning on slide 7. Commercial banking continues to perform at a high level. Growing loans, revenue and economic profit. Are there any regional and national recognition form its middle market customers for excellence in client service. Commercial banking loans improve 5% linked quarter and 16 and a half year over year propelled by record quarterly originations of over 900 million. And record fundings of over 660 million.
Reflecting both strong lending activity and new customer acquisition across all business units at all geographies. Anticipated Q1 pay-offs combined with a smaller pipeline due to exceptionally strong loan conversion in Q4 may affect loan growth near term. The portfolio yields a client one basis performing quarter for the decline in the yield on new findings, reflects origination mix more than competitive pricing pressure. Q4 similar to Q2 sold a greater proportions of high quality lower investor CRE funding representing 31% of Q4 commercial originations. Compared to 10% in Q3. We continue to exhibit strong pricing discipline in the commercial bank. SNP which each quarter provides objective pricing information on our loan originations and portfolio compared to the market. Recently, applying that compared to our peers, Webster’s use more selective use of price as a key lever to win business. As resulted in margins remaining at a premium to the market.
The overall deposit decrease link quarter reflect seasonality in municipal deposits. Transaction deposits increase 12% linked quarter and now represent 64% of total commercial deposits up for 52% a year ago. This accounts for the year over year decline in deposit costs and evidence is strong momentum in establishing and growing primary bank relationships. On slide 8 for the full year 2014, the commercial banking segment posted positive operating leverage of over 8%. PPNR is growing rapidly and consistently since 2010.
Moving on community banking, slide 9 shows banking unit continues to grow both, higher originations 3 % link quarters and 20 % years over of loan growth. The portfolio is increased by 11 basis link quarter which equates to approximately 3 basis points in loan yield for the quarter. In summary the lower securities yield and unchanged loan yield resulted in a net reduction of 1 basis point in the earning asset yield. The reduction was more than offset by an increase in average earning assets resulting in 3.7 million increase in interest income. Average deposits increased 19 million. Demand deposits increased by 63 million or two percent offset by seasonal outflows in public deposits. The rate paid on deposits was 29 basis points for third straight quarter with a one basis point decline in cost of core deposits offsetting at 3 basis point increase in CDs. Average borrowings increased by 415 million while the average cost declined by 7 basis points.
The incremental funding was primarily short termed FHOB advances at a cost of around 22 basis points. The net result in Q4 was a increase of about 600,000 in interest expense on borrowings. We expect short term borrowings to fall by about 1 million on average in Q1 due to the HSA acquisition and seasonal growth in public deposits. In summary earning asset growth and a stable name resulted in a 3.2 million increase in net interest income. Slide 18 provides details details on core non-interest income which increased 2.5 million or 5 percent versus prior quarter. Loan fees increased 2.9 million linked quarter as a result of pre-payment revenue. Other income increased 1.4 million primarily from Bowly proceeds. This was off-set by lower mortgage banking revenue as a result of a nine percent linked quarter decrease in settlement buying along with modest declines in deposit fees. Slide 19 highlights our core non-interest expense which was up 2.7 million from both Q3 and prior year.
