| 1965 | 1 |
| 1966 | 1 |
| 1967 | 10 |
| 1968 | 14 |
| 1969 | 23 |
| 1970 | 20 |
| 1971 | 23 |
| 1972 | 35 |
| 1973 | 51 |
| 1974 | 58 |
| 1975 | 77 |
| 1976 | 74 |
| 1977 | 80 |
| 1978 | 91 |
| 1979 | 105 |
| 1980 | 115 |
| 1981 | 127 |
| 1982 | 129 |
| 1983 | 144 |
| 1984 | 169 |
| 1985 | 194 |
| 1986 | 203 |
| 1987 | 156 |
| 1988 | 211 |
| 1989 | 216 |
| 1990 | 153 |
| 1991 | 170 |
| 1992 | 201 |
| 1993 | 158 |
| 1994 | 206 |
| 1995 | 213 |
| 1996 | 188 |
| 1997 | 184 |
| 1998 | 339 |
| 1999 | 325 |
| 2000 | 341 |
| 2001 | 393 |
| 2002 | 351 |
| 2003 | 454 |
| 2004 | 474 |
| 2005 | 450 |
| 2006 | 529 |
| 2007 | 654 |
| 2008 | 502 |
| 2009 | 464 |
| 2010 | 497 |
| 2011 | 510 |
| 2012 | 463 |
| 2013 | 585 |
| 2014 | 606 |
| 2015 | 593 |
| 2016 | 577 |
| 2017 | 492 |
| 2018 | 482 |
| 2019 | 574 |
| 2020 | 504 |
| 2021 | 531 |
| 2022 | 624 |
| 2023 | 544 |
| 2024 | 425 |
| 2025 | 24 |
| not yet published | 2 |