Year	Number of
1990	147.02
1991	153.7
1992	162.77
1993	169.63
1994	177.19
1995	179.92
1996	187.28
1997	192.68
1998	195.02
1999	200.24
2000	203.13
2001	209.07
2002	219.1
2003	229.1
2004	237.63
2005	244.4
2006	253.18
2007	262.15
2008	269.07
2009	275.15
2010	284.05
2011	289.44
2012	299.9
2013	312.2
2014	318.77
2015	324.88
2016	330.68