| # covers | # covers | % covers | % covers | ||
| w/A-A's | w/C-A's | Total | w/A-A's | w/C-A's | |
| 1936-1939 | 1 | 88 | 89 | 1.1% | 98.9% |
| 1940-1949 | 0 | 347 | 347 | 0.0% | 100.0% |
| 1950-1959 | 6 | 272 | 278 | 2.2% | 97.8% |
| Total | 7 | 707 | 714 | 1.0% | 99.0% |
| 1960-1969 | 15 | 210 | 225 | 6.7% | 93.3% |
| 1970-1979 | 7 | 88 | 95 | 7.4% | 92.6% |
| 1980-1989 | 3 | 48 | 51 | 5.9% | 94.1% |
| 1990-2000 | 2 | 52 | 54 | 3.7% | 96.3% |
| Total | 27 | 398 | 425 | 6.4% | 93.6% |