Year	Number of
1990	71.06
1991	73.07
1992	75.35
1993	77.85
1994	80.51
1995	83.34
1996	85.54
1997	87.78
1998	90.07
1999	92.41
2000	94.89
2001	96.58
2002	98.4
2003	100.35
2004	102.44
2005	104.75
2006	106.2
2007	107.78
2008	109.66
2009	111.73
2010	114.03
2011	115.27
2012	116.68
2013	118.12
2014	119.75
2015	121.61
2016	123.6
