( figures in italic indicate the total number of foreign-bred horses which entered Graded Races )
| Year | Races Run (1) | Races for Foreign-bred Horses (2) | (2) / (1) (%) | Total Number of Foreign-bred Runners | Total Number of Runners | Ratio of Foreign-breds (%) |
| 1990 | 108 | 47 | 43.5% | 20 | ||
| 3,353 | 784 | 23.4% | 390 | 38,397 | 1.02 | |
| 1991 | 108 | 50 | 46.3% | 25 | ||
| 3,389 | 959 | 28.3% | 539 | 38,911 | 1.39 | |
| 1992 | 108 | 55 | 50.9% | 46 | ||
| 3,399 | 1,104 | 32.5% | 719 | 40,193 | 1.79 | |
| 1993 | 108 | 65 | 60.2% | 77 | ||
| 3,425 | 1,334 | 38.9% | 850 | 40,776 | 2.08 | |
| 1994 | 113 | 78 | 69.0% | 124 | ||
| 3,429 | 1,478 | 43.1% | 1,412 | 41,181 | 3.43 | |
| 1995 | 113 | 86 | 76.1% | 151 | ||
| 3,431 | 1,578 | 46.0% | 2,448 | 42,801 | 5.72 | |
| 1996 | 122 | 97 | 79.5% | 284 | ||
| 3,435 | 1,624 | 47.3% | 3,649 | 42,782 | 8.53 | |
| 1997 | 124 | 98 | 79.0% | 333 | ||
| 3,440 | 1,700 | 49.4% | 4,680 | 43,876 | 10.67 | |
| 1998 | 125 | 103 | 82.4% | 341 | ||
| 3,450 | 1,798 | 52.1% | 5,381 | 44,517 | 12.09 | |
| 1999 | 127 | 108 | 85.0% | 362 | ||
| 3,415 | 1,884 | 55.2% | 5,187 | 44,321 | 11.70 | |
| 2000 | 127 | 109 | 85.8% | 408 | ||
| 3,451 | 1,898 | 55.0% | 4,709 | 45,815 | 10.28 | |
| 2001 | 128 | 110 | 85.9% | 335 | ||
| 3,448 | 1,897 | 55.0% | 4,641 | 47,382 | 9.79 | |
| 2002 | 128 | 111 | 86.7% | 300 | ||
| 3,452 | 1,900 | 55.0% | 4,524 | 48,920 | 9.25 | |
| 2003 | 127 | 110 | 86.6% | 238 | ||
| 3,451 | 1,899 | 55.0% | 4,118 | 49,057 | 8.39 | |
| 2004 | 129 | 115 | 89.1% | 212 | ||
| 3,452 | 1,900 | 55.0% | 3,546 | 47,533 | 7.46 |