Year	Number of
1990	113.35
1991	114.55
1992	116.16
1993	118.13
1994	120.32
1995	122.69
1996	123.3
1997	124.16
1998	125.19
1999	126.51
2000	128.17
2001	130.77
2002	133.74
2003	137.04
2004	140.78
2005	145
2006	149.65
2007	154.71
2008	160.22
2009	166.16
2010	172.6
2011	178.04
2012	183.91
2013	189.99
2014	196.52
2015	203.56
2016	211.68