Year	Number of
1990	192347.6
1991	198727.06
1992	206508.94
1993	215379.18
1994	224511.48
1995	230799.1
1996	239355.73
1997	246849.73
1998	254708
1999	260805.97
2000	266603.61
2001	270937.42
2002	274008.73
2003	273477.11
2004	275686.92
2005	277369.95
2006	276121.52
2007	277032.99
2008	278725.64
2009	280278.08
2010	281510.66
2011	283185.49
2012	287326.18
2013	293602.68
2014	303353.29
2015	312994.85
2016	323638.29