| Year | Rank | Number |
| 2010 | 15884 | 6 |
| 2008 | 10383 | 11 |
| 2007 | 14622 | 7 |
| 2001 | 16582 | 5 |
| 1995 | 14474 | 5 |
| 1989 | 13328 | 5 |
| 1983 | 11015 | 5 |
| 1982 | 9735 | 6 |
| 1979 | 8430 | 7 |
| 1977 | 7899 | 7 |
| 1976 | 7644 | 7 |
| 1975 | 9700 | 5 |
| 1974 | 5971 | 9 |
| 1973 | 8983 | 5 |
| 1972 | 6219 | 8 |
| 1971 | 6270 | 8 |
| 1970 | 4611 | 12 |
| 1969 | 7000 | 6 |
| 1968 | 7513 | 5 |
| 1967 | 6361 | 6 |
| 1966 | 5045 | 8 |
| 1965 | 6962 | 5 |
| 1964 | 5721 | 7 |
| 1961 | 6184 | 6 |
| 1960 | 6002 | 6 |
| 1956 | 6392 | 5 |