Year	Number of
1990	5501.15
1991	5770.4
1992	6092.57
1993	6399.31
1994	6720.91
1995	7051.07
1996	7339
1997	7618.88
1998	7968.19
1999	8289.74
2000	8656.29
2001	9079.61
2002	9545.71
2003	10032.93
2004	10547.78
2005	11110.45
2006	11622.29
2007	12227.22
2008	12883.88
2009	13542.52
2010	14189.51
2011	14753.75
2012	15308.66
2013	15798.83
2014	16107.99
2015	16203.52
2016	16469.63