Year	Number of
1990	194.05
1991	201.56
1992	209.68
1993	218.38
1994	227.7
1995	237.74
1996	245.47
1997	253.77
1998	262.5
1999	271.58
2000	281.1
2001	285.84
2002	290.8
2003	296.13
2004	302.08
2005	308.96
2006	316.92
2007	325.76
2008	335.63
2009	345.92
2010	356.55
2011	369.15
2012	382.14
2013	395.54
2014	409.64
2015	424.68
2016	440.58