The sales data for May apartment transactions was released yesterday by New York City-based Real Capital Analytics (RCA) and the numbers didn’t disappoint.

Last month saw the highest monthly total in multifamily sales volume so far in 2012, with $5.5 billion changing hands. That brings the year-to-date total sales volume to $22.1 billion as of June 1.

Among the largest transactions last month was a partnership between New York City-based Gaia Real Estate and Greenwich, Conn.-based Starwood Capital Group that purchased a 32-property portfolio of just over 9,500 units for approximately $446 million. The other large deal in May came when Sacramento, Calif.-based CalSTRS bought a 90 percent stake in nearly 5,000 units spread across 14 properties for approximately $820 million.

Some of the regions that lead in high sales volume this year are Manhattan, where 134 properties have traded for almost $2.6 billion; Los Angeles, where 156 properties were traded for $1.2 billion; Dallas, where 70 properties were traded for $867 million; and Atlanta, where 66 properties were sold for $1.2 billion.

The report projects that the sales figures for the second quarter of 2012 will surpass the first quarter, and notes that May sales were up 15 percent year-over-year.