Year	Number of
1990	70.55
1991	71.98
1992	73.6
1993	75.65
1994	77.45
1995	79.66
1996	80.38
1997	83.53
1998	85.95
1999	88.26
2000	90.35
2001	92.16
2002	93.81
2003	95.42
2004	96.68
2005	97.4
2006	98.72
2007	100.75
2008	102.05
2009	103.71
2010	104.92
2011	109.72
2012	113.38
2013	116.56
2014	120.63
2015	126
2016	132.16