i don't see any 24-Valve badges on your car so i'm assuming it was a 3.1? if so it was one of 499 made. i'm actually looking into a '92 DOHC STE right now:
http://www.gmwbody.com/viewtopic.php?t=216
I finally got some good STE production numbers from Pontiac.
1990
4-Door Sedan - STE (all) 5,773
Turbos - 1,000
1991
4-Door Sedan - STE (all) 4,308
w/3.1L V-6 - 3,391
w/3.4L V-6 - Manual - 125
w/3.4L V-6 - Auto - 792
1992
4-Door Sedan - STE (all) 1,127
w/3.1L V-6 - 499
w/3.4L V-6 - Manual - 57
w/3.4L V-6 - Auto - 571
1993
4-Door Sedan - STE (all) 533
w/3.1L V-6 - 172
w/3.4L V-6 - Manual - 1
w/3.4L V-6 - Auto - 360
They also sent me this RPO code info. Im not sure which years this applies too, or if it applies to all years but here's some more info. The way it seems from the email these might apply to each year.
Regular Production Option = RPO Code
RPO Description Totals
Leather Beige 82
Leather Graphite 219
CF5 Sunroof 257
UV6 HUD 237
U1A Compact Disc 166