| Covers listed |
|
| 1966: | December, |
| 1967: | January, February, March, April, June, December, |
| 1968: | February, March, April, May, June, July, August, September, October, November, December, |
| 1969: | January, February, March, April, May, June, November, |
| 1970: | February, July, October, November, |
| 1971: | January, September, October, November, |
| 1972: | January, February, March, April, June, August, |
| 1973: | January, February, March, May, May, August, November, |
| 1974: | April, July, September, November, |
| 1975: | January, February, March, May, June, August, September, December, |
| 1978: | July, |
| 1980: | December, |
| 1981: | January, |
| 1983: | September, |
| 1984: | March, April, September, October, |
| 1985: | April, May, August, October, |
| 1986: | August, September, |
| 1987: | March, May, August, October, |
| 1988: | January, February, June, August, October, |
| 1990: | February, June, |
| 1991: | February, April, |
