Year	Number of
1990	4110.69
1991	4404.52
1992	4730.92
1993	5090.53
1994	5486.25
1995	5921.97
1996	6355.37
1997	6825.36
1998	7334.96
1999	7888.74
2000	8492.22
2001	8972.2
2002	9484.05
2003	10024.6
2004	10590.63
2005	11188.84
2006	11854.03
2007	12550.6
2008	13307.02
2009	14121.48
2010	14998.12
2011	15458.08
2012	15963.8
2013	16492.35
2014	17035.46
2015	17588.18
2016	18144.84