Deferred income on shipments into distribution increased modestly by $378,000, as our shipments to our US distributors were marginally greater than what they shipped out to their end customers. Our accounting is conservative as we do not record a sale on our books until distribution has made a sale to their end customer.
Worldwide, we continue to believe our inventory levels are lean. We continue to closely control our inventory at distributors to properly position the inventory relative to potential demand. In total, current liabilities are relatively small and therefore we have a strong current ratio. Our current ratio was 8.4:1 versus last quarter’s 7:1. Deferred tax and other long-term liabilities of $120.3 million increased by $10.4 million largely due to increases in long-term taxes on various tax timing difference. Changes in the stockholder equity accounts were primarily the result of the usual quarterly transactions for net income, dividends paid and employee stock activity. As stated earlier, the company announced it will pay a quarterly dividend of $0.30 per share. The company believes that paying a dividend is an important way to return value to its shareholders. The company began paying a dividend in 1992 and has increased it every year since and currently pays approximately a 2.7% yield.
Looking forward. We are coming into the second half of our fiscal year, which is normally our strongest half. The March quarter is historically a strong quarter for two of our largest end-markets: industrial and automotive. The following factors impact our guidance. On the macroeconomic upfront, the US economy is strong and is projecting stronger growth than reported in recent years. On the other hand Europe, China and Japan are experiencing reductions in growth. The dollar is strong, which has pluses and minuses. Similarly, oil prices are low which also has positive and negative economic effects. From a Linear-specific standpoint, we have a positive book-to-bill ratio going into the March quarter. We had good bookings momentum at the end of December, and so far bookings have been off to a good start in January. Chinese New Year is this quarter. Our foreign factories will be closed for a week. It is always interesting to monitor Asia momentum post the New Year holiday. Finally, we continue to believe inventory at customers are lean based on our continuing minor cancellation activity. Summarizing these various data points has given us a positive bias in the short-term. Consequently, we are currently forecasting revenues for the March quarter to grow, sequentially in the 4% to 7% range. Depending on sales, operating margin as a percent of sales should improve modestly. Our ongoing effective tax rate should be roughly 25.5% prior to discrete items if any that may arise.
In summary, looking beyond these near-term market events, the major market opportunities that drive our business demonstrate continuing growth, particularly in the industrial and automotive end-markets. Increased analog innovations in our other end-markets will also benefit us. We believe we are in the right markets at the right time with the right innovative products, execute our strategy and exploit our growth opportunities. We are strong in the areas we want to be: industrial, communications infrastructure and networking and automotive, and believe that we are in an innovation-driven environment. Our strategy is differentiated from our other analog competitors. We dominate in different end-markets, we are more reliable supplier with consistently lower lead times and better support and our technology and support is valued as is evidenced by our higher operating margin.
Finally, at this time of year, we review our dividend. We have increased the dividend every year, although modestly in the last several years, as we have accumulated cash to pay down our debt. In May 2014, we extinguish the debt. Consequently, going forward, we are able to return more current cash to shareholders. Therefore we have announced increasing our quarterly cash dividend by 11% from $0.27 a share to $0.30 a year share.
