Year	Number of
1990	10877.4
1991	11222.36
1992	11594.36
1993	11992.88
1994	12419.5
1995	12879.3
1996	13087.27
1997	13321.66
1998	13577.85
1999	13855.73
2000	14159.1
2001	14259.79
2002	14387.95
2003	14538.46
2004	14712.09
2005	14913.54
2006	14911.69
2007	14932.42
2008	14981.38
2009	15049.91
2010	15138.57
2011	15707.4
2012	16317.02
2013	16965.19
2014	17657.89
2015	18397.57
2016	19131.89