1988 - 124 STEs out of the 1,938 STEs built got AWD as an option.
1989 - 1,376 total STEs built, all receiving standard AWD.
1990 - Unknown number of the 5,599 total SEs built received the AWD as an option (GM didn't seperate the AWD figures from the total number of SEs made).
The STE package was dropped after '89, and moved to the premium 4-door GP trim level (from '90 - '93). Thus why the SEs got the AWD package in '90, and '90 only. The 6000 was dropped all together after '91, rather then going through the redesigning phase with the rest of the GM cars.