Note: Jan. 2018 data shown below is the most recent published by National Association of Realtors.

Sales of existing homes in January dipped for the second straight month, and saw their most significant decline on an annual basis in more than three years. Data from the National Association of Realtors® (NAR) indicates that all major regions saw monthly and annual sales declines last month.

Total existing-home sales (completed transactions for single-family homes, townhomes, condominiums and co-ops), fell 3.2% in January to 5.38 million from 5.56 million in December 2017. Sales are 4.8% lower than a year ago (largest annual decline since August 2014 at 5.5%) and sit at their slowest pace since last September (5.37 million).

NAR’s chief economist, Lawrence Yun, said that January’s downturn in closings underscores the housing market’s major inventory shortage. “The utter lack of sufficient housing supply and its influence on higher home prices muted overall sales activity in much of the U.S. last month,” Yun said. “While the good news is that Realtors® in most areas are saying buyer traffic is even stronger than the beginning of last year, sales failed to follow course and far lagged last January’s pace. It’s very clear that too many markets right now are becoming less affordable and desperately need more new listings to calm the speedy price growth.”

January’s U.S. median existing-home price (all housing types) was $240,500, up 5.8% from January 2017 ($227,300). January’s price increase represents the 71st straight month of year-over-year gains.

American total housing inventory at the end of January grew 4.1% to 1.52 million existing homes available for sale, but is still 9.5% below a year ago (1.68 million) and has fallen year-over-year for 32 straight months. Unsold inventory sits at a 3.4-month supply at the current sales pace.

First-time buyers drive 29% of sales in January, which is down from 32% in December 2017 and 33% one year ago. The annual share of first-time buyers was 34%.

Freddie Mac data shows the average commitment rate for a 30-year, conventional, fixed-rate mortgage got a boost for the fourth consecutive month to 4.03% in January from 3.95% in December. The average commitment rate for all of 2017 was 3.99%.

All-cash sales were 22% of transactions in January, which is up from 20% in December 2017 but down from 23% a year ago.