Our single-family serious delinquency rate remained near historically low levels at 55 basis points as of December 31, compared to 65 basis points as of the end of 2022. In addition to market factors, this is a testament to the enhanced underwriting policies, loan workout options, and support we give to lenders and borrowers. Turning to our credit risk transfer program, in 2023, we executed 17 single-family credit risk transfer transactions between our Connecticut Avenue Securities and Credit Insurance Risk Transfer programs, transferring a portion of the credit risk on approximately $308 billion of unpaid principal balance at the time of the transactions. We paid $1.4 billion in annual premiums in 2023 on our outstanding single-family credit risk transfer transactions.
Now in multi-family, we reported $2.6 billion in net income in 2023, an increase of $400 million, compared to 2022. This was primarily due to a decrease in the provision for credit losses year-over-year. In 2022, we recorded a $1.2 billion provision for multi-family credit losses, mostly driven by our seniors housing loans. In 2023, we recorded a $495 million provision for multi-family credit losses, due primarily to changes in loan activity and declining property values on our overall multifamily book. Our seniors housing loans did not drive our multi-family provision for credit losses in 2023, because of loss mitigation activities we performed last year and some recovery and property financials. However, our allowance for seniors’ housing loans remained elevated.
Turning to our acquisitions, we acquired $53 billion in multi-family loans last year, down 24% from 2022. Continued market uncertainty and high interest rates kept total market volumes low. Based on our analysis, we met the mission requirements set forth by FHFA for last year that required that at least 50% of our 2023 multi-family business volume focus on certain affordable and underserved market segments. The multi-family loans we acquired in 2023 had a weighted average original loan-to-value ratio of 59%. These loans also had a weighted average debt service coverage ratio of 1.6 times. The overall credit profile of our multi-family book remains strong, with a weighted average original loan-to-value ratio of 63% and a weighted average debt service coverage ratio of 2 times.
We continue to monitor the impacts of elevated interest rates on our multi-family book. Higher rates may reduce the ability of multi-family borrowers to refinance their loans prior to maturity when they typically have a balloon payment due. Our near-term maturities remain low, roughly 2% of our multi-family book is expected to mature in 2024, and approximately 3.5% is expected to mature in 2025. Elevated interest rates also result in higher monthly payments for borrowers with adjustable rate mortgages, which may lower their debt service coverage ratios. As of the end of December, adjustable rate mortgages made up about 9% of our multi-family book. Our multi-family serious delinquency rate increased to 46 basis points as of December 31, 2023 from 24 basis points as of the same time the prior year, driven by stress in our seniors’ housing loans.
We actively pursue loss mitigation actions when appropriate, such as loan workouts, which may resolve delinquencies. If appropriate workouts cannot be achieved, the loans are foreclosed upon. Our multi-family serious delinquency rate as of December 31 is down from the recent peak of 54 basis points as of September 30, because of these loss mitigation actions and foreclosures. We expect these activities will continue into 2024, which may further decrease our multi-family serious delinquency rate. Our primary form of multi-family risk sharing is our delegated underwriting and servicing, or DUS program, which shares risk on the loans we acquire with our network of DUS lenders. In addition to this risk sharing in 2023, we completed two multi-family credit risk transfer transactions, which transferred a portion of the credit risk on nearly $31 billion of unpaid principal balance at the time of the transactions.
Turning to capital as of the end of the year, we remain significantly undercapitalized with a $243 billion shortfall to the amount of capital needed to be fully capitalized. This was a $15 billion improvement, compared to the $258 billion shortfall at the end of 2022. Before we close out today, I’ll share some thoughts on our macroeconomic outlook for 2024. Our economists have replaced their call for a modest recession with an expectation for positive, but below-trend growth in 2024. However, heightened uncertainty and significant downside risks, including geopolitical risks, remain and in their view, the economy still faces a higher than normal risk of recession. The market expects the Federal Reserve to cut interest rates this year, which we believe will lead to a further pullback in mortgage rates.
We currently expect the 30-year fixed rate mortgage rate to average 6.1% in 2024, while affordability challenges, the lock-in effect, and a low inventory of homes available for sale will likely persist, single-family home sales are expected to begin a slow recovery. Because of this, we expect single-family mortgage originations to grow from $1.5 trillion in 2023 to nearly $2 trillion in 2024. Purchases are likely to continue to dominate the market given the rate environment, and we estimate they will make up approximately 75% of single-family mortgage originations this year. In the multi-family market, we expect to continue to see similar trends in 2024 that we saw last year. Given elevated interest rates, abundant supply in some markets, and muted rent growth, we believe multi-family housing starts will likely decline this year.
