If one uses a three year window, it’s three times: February, 1986, May 1995, September 1997. Three other times, a recession follows.
The last time around — when people were saying “this time is different” — was May 2005. Inversion occurred in February 2006 (and in November 2006, skepticism of impending recession). The recession is dated by NBER as starting in December 2007.