Year	Number of
1990	124.06
1991	124.73
1992	128.53
1993	132.98
1994	133.61
1995	138.09
1996	137.03
1997	137.04
1998	138.06
1999	141.48
2000	152.4
2001	158.54
2002	165.61
2003	175.67
2004	182.62
2005	189.03
2006	196.11
2007	196.11
2008	200.7
2009	204.17
2010	209.46
2011	217.99
2012	227.47
2013	242.2
2014	256.95
2015	269.51
2016	283.43