Year	Number of
1990	191.05
1991	183.72
1992	185.9
1993	188.57
1994	189.09
1995	194.55
1996	192.05
1997	194.8
1998	198.73
1999	207.73
2000	217.38
2001	230.73
2002	239.12
2003	254.51
2004	266.89
2005	283.05
2006	297.66
2007	312.65
2008	325.83
2009	343.38
2010	362.35
2011	378.61
2012	394.79
2013	410.96
2014	427.18
2015	444.91
2016	462.92