Year	Number of
1990	132.74
1991	143.43
1992	155.14
1993	167.62
1994	181.84
1995	197.32
1996	213.78
1997	231.68
1998	251.76
1999	275.23
2000	300.5
2001	321.94
2002	344.26
2003	369.27
2004	397.25
2005	425.3
2006	458.59
2007	480.27
2008	517.88
2009	561.13
2010	603.34
2011	649.76
2012	682.81
2013	717.46
2014	754.54
2015	794.32
2016	839.51