Year	Number of
1990	86.63
1991	84.85
1992	83.41
1993	81.42
1994	80.09
1995	79.14
1996	79.99
1997	80.25
1998	79.97
1999	80.92
2000	82.52
2001	83.1
2002	83.83
2003	84.16
2004	84.91
2005	85.61
2006	88.16
2007	90.48
2008	92.97
2009	95.78
2010	99.33
2011	101.4
2012	103.34
2013	105.89
2014	108.86
2015	112.39
2016	116.46