Year	Number of
1990	15071.86
1991	15458.85
1992	15885.38
1993	16356
1994	16852.58
1995	17391.22
1996	17613.19
1997	17846.15
1998	18092.62
1999	18328.31
2000	18583.95
2001	18888.55
2002	19235.9
2003	19636.76
2004	20048.73
2005	20475.15
2006	20808.89
2007	21169.34
2008	21525.25
2009	21843.44
2010	22165.85
2011	22415.15
2012	22631.74
2013	22823.15
2014	23017.07
2015	23234.99
2016	23465.96