| 2016 |
15,998,416 |
| 2015 |
15,620,312 |
| 2014 |
15,417,032 |
| 2013 |
15,378,206 |
| 2012 |
15,374,230 |
| 2011 |
15,507,284 |
| 2010 |
15,553,387 |
| 2009 |
15,556,658 |
| 2008 |
15,579,603 |
| 2007 |
15,491,878 |
| 2006 |
15,272,680 |
| 2005 |
15,007,005 |
| 2004 |
14,847,416 |
| 2003 |
14,604,720 |
| 2002 |
14,346,373 |
| 2001 |
14,041,846 |
| 2000 |
13,398,895 |
| 1999 |
13,012,132 |
| 1998 |
12,691,835 |
| 1997 |
12,343,598 |
| 1996 |
12,019,156 |
| 1995 |
11,992,578 |
| 1994 |
10,762,041 |
| 1993 |
10,537,677 |
| 1992 |
9,692,974 |
| 1991 |
9,231,405 |
|