Year	Number of
1990	106.12
1991	109.93
1992	113.4
1993	116.21
1994	119.03
1995	122.87
1996	125.78
1997	129.18
1998	133.35
1999	137.53
2000	141.29
2001	146.87
2002	153.24
2003	158.45
2004	164.55
2005	170.93
2006	176.83
2007	182.18
2008	187.25
2009	192.3
2010	196.71
2011	200.71
2012	204.19
2013	207.27
2014	210.8
2015	214
2016	217.58