| Covers listed | |
| 1977: | July, |
| 1988: | January, |
| 1989: | October, November, December, |
| 1990: | January, June, July, August, September, October, November, |
| 1991: | February, |
| 1992: | December, |
| 1993: | April, October, |
| 1994: | April, July, |
| 1995: | August, |
| 1997: | February, May, November, |
| 1998: | February, |
