Year	Number of
1990	88.85
1991	96.66
1992	106.51
1993	119.7
1994	134.24
1995	150.05
1996	165.53
1997	177.56
1998	186.75
1999	192.64
2000	193.77
2001	195.63
2002	198.25
2003	202.19
2004	208.49
2005	211.04
2006	215.74
2007	217.48
2008	221.52
2009	225.06
2010	228.11
2011	231.29
2012	235.86
2013	248.17
2014	259.45
2015	271.07
2016	282.66