Year	Number of
1990	85.64
1991	96.27
1992	105.68
1993	116.79
1994	127.93
1995	140.25
1996	151.6
1997	162.49
1998	174.61
1999	186.88
2000	202.25
2001	215.58
2002	230.39
2003	248.34
2004	260.3
2005	272.89
2006	285.67
2007	296.74
2008	309.55
2009	322.24
2010	337.54
2011	353.6
2012	364.31
2013	378.84
2014	394.19
2015	409.57
2016	429.24