Year	Number of
1990	12303.4
1991	12546.91
1992	12645.98
1993	12936.1
1994	13176.37
1995	13436.68
1996	13435.28
1997	13612.31
1998	13606.36
1999	14208.64
2000	14055.36
2001	14104.05
2002	13969.4
2003	14517.57
2004	14857.48
2005	15354.41
2006	15545.38
2007	15316.77
2008	15124.38
2009	16243.07
2010	16636.77
2011	16945.44
2012	17056.99
2013	17536.63
2014	17621.35
2015	17811.57
2016	18141.33