Year	Number of
1990	196.08
1991	201.57
1992	201.13
1993	201.99
1994	203.2
1995	205.17
1996	209.42
1997	213.92
1998	218.73
1999	225.65
2000	233.36
2001	243.29
2002	253.77
2003	264.44
2004	275.29
2005	286.43
2006	296.25
2007	308.75
2008	322.55
2009	336.81
2010	351.51
2011	367.76
2012	385.43
2013	404.17
2014	423.2
2015	445.32
2016	467.65