Year	Number of
1990	71.63
1991	73.43
1992	75.5
1993	77.78
1994	80.2
1995	82.77
1996	84.86
1997	86.98
1998	89.11
1999	91.29
2000	93.61
2001	95.46
2002	97.44
2003	99.52
2004	101.72
2005	104.13
2006	105.89
2007	107.8
2008	110
2009	112.4
2010	115.01
2011	117.01
2012	119.15
2013	121.35
2014	123.76
2015	126.44
2016	129.37