Year	Number of
1990	105.46
1991	109.26
1992	113.72
1993	118.9
1994	124.01
1995	129.96
1996	134.78
1997	142.26
1998	149.62
1999	157.54
2000	166.41
2001	172.92
2002	180.33
2003	187.49
2004	194.64
2005	201.13
2006	207.26
2007	218.42
2008	226.5
2009	234.6
2010	242.69
2011	256.63
2012	267.33
2013	278.36
2014	291.41
2015	306.27
2016	319.93