Year	Number of
1990	62.91
1991	65.61
1992	68.35
1993	70.54
1994	72.95
1995	76.03
1996	78.27
1997	81.8
1998	84.02
1999	83.43
2000	87.81
2001	91.38
2002	92.18
2003	98.06
2004	102.51
2005	105.02
2006	109.1
2007	112.99
2008	116.21
2009	116.51
2010	120.17
2011	121.96
2012	124.15
2013	123.53
2014	125.78
2015	125.61
2016	125.04