Year	Number of
1990	189.3
1991	195.94
1992	202.98
1993	211.23
1994	218.96
1995	227.24
1996	231.47
1997	235.41
1998	237.42
1999	240.78
2000	243.97
2001	246.85
2002	249.62
2003	251.58
2004	253.36
2005	255.02
2006	256.34
2007	258.83
2008	262.11
2009	266.26
2010	270.26
2011	275.14
2012	278.98
2013	282.29
2014	286.73
2015	295.43
2016	304.89