Track Trends
| Year | Start | End | Days | Races | Avg. Att. | Avg. Han. |
| 1966 | January 8 | February 12 | 22 | 198 | 10,106 | 997,048 |
| 1967 | January 3 | March 3 | 48 | 432 | 11,109 | 1,143,138 |
| 1968 | February 12 | April 20 | 52 | 469 | 11,199 | 1,170,790 |
| 1969 | January 6 | March 6 | 52 | 468 | 10,908 | 1,237,738 |
| 1970 | January 5 | March 7 | 52 | 468 | 9,819 | 1,087,988 |
| 1971 | February 8 | April 17 | 59 | 531 | 10,410 | 1,115,870 |
| 1972 | January 1 | March 11 | 57 | 513 | 9,761 | 1,072,547 |
| 1973 | January 2 | March 12 | 60 | 540 | 9,516 | 1,075,714 |
| 1974 | January 2 | March 16 | 60 | 540 | 8,663 | 1,037,646 |
| 1975 | January 6 | March 15 | 56 | 504 | 9,223 | 1,099,773 |
| 1976 | January 1 | March 12 | 58 | 522 | 8,816 | 1,071,326 |
| 1977 | January 3 | March 11 | 53 | 483 | 8,778 | 1,063,267 |
| 1978 | January 3 | March 17 | 52 | 505 | 8,494 | 1,079,001 |
| 1979 | January 1 | March 31 | 72 | 641 | 7,997 | 1,021,954 |
| 1980 | January 1 | March 14 | 62 | 561 | 7,961 | 1,092,628 |
| 1981 | January 1 | March 14 | 60 | 553 | 7,736 | 1,092,216 |
| 1982 | January 1 | March 12 | 57 | 513 | 7,623 | 1,039,596 |
| 1983 | January 3 | March 15 | 59 | 531 | 7,412 | 1,036,963 |
| 1984 | January 2 | March 13 | 58 | 522 | 6,934 | 974,191 |
| 1985 | January 1 | January 19 | 15 | 127 | 6,683 | 1,002,862 |