ALBANY — Three-quarters of the way into this fiscal year, New York’s public pension fund investments are enjoying a 22 percent rebound, and state officials think they know why.

State Comptroller Thomas DiNapoli yesterday credited a diversity of investments and a long-term perspective for the surprise turnaround through the end of December.

At about $129 billion, the fund is still shy of the historic $154 billion of spring 2008 — before it lost tens of billions of dollars in value to falling markets.

The state pension system has about 350,000 retirees and 650,000 active members.