Year	Number of
1990	63.03
1991	65.13
1992	67.68
1993	70.84
1994	74.26
1995	77.84
1996	80.82
1997	83.98
1998	87.01
1999	90.05
2000	93.15
2001	94.82
2002	96.53
2003	98.89
2004	101.47
2005	104.35
2006	106.29
2007	108.34
2008	110.73
2009	113.08
2010	115.35
2011	118.53
2012	121.85
2013	124.47
2014	127.43
2015	130.86
2016	134.64