| Year | File Count |
|---|---|
| 1982 | 79 |
| 1983 | 46 |
| 1984 | 6372 |
| 1985 | 31752 |
| 1986 | 30018 |
| 1987 | 38751 |
| 1988 | 50297 |
| 1989 | 56744 |
| 1990 | 53403 |
| 1991 | 83989 |
| 1992 | 86108 |
| 1993 | 81521 |
| 1994 | 51559 |
| 1995 | 54914 |
| 1996 | 39496 |
| 1997 | 45667 |
| 1998 | 44795 |
| 1999 | 65534 |
| 2000 | 99284 |
| 2001 | 84328 |
| 2002 | 84803 |
| 2003 | 63968 |
| 2004 | 129294 |
| 2005 | 129122 |
| 2006 | 181794 |
| 2007 | 222554 |
| 2008 | 238135 |
| 2009 | 275410 |
| 2010 | 317614 |
| 2011 | 176936 |
| 2012 | 193605 |
| 2013 | 432138 |
| 2014 | 563407 |
| 2015 | 588909 |
| 2016 | 579106 |
| 2017 | 546107 |
| 2018 | 254346 |
| 2019 | 8288 |