Year	Number of
1990	133.06
1991	140.08
1992	147.96
1993	157.2
1994	167.21
1995	177.91
1996	188.23
1997	198.57
1998	207.54
1999	216.43
2000	218.8
2001	221.69
2002	225.22
2003	230.03
2004	234.08
2005	241.67
2006	251.15
2007	260.66
2008	271.1
2009	281.85
2010	293.53
2011	305.24
2012	316.37
2013	331.22
2014	346.57
2015	362.92
2016	380.18