Year	Number of
1990	94.47
1991	95.51
1992	99.51
1993	103.61
1994	108.37
1995	113.84
1996	119.73
1997	125.81
1998	131.73
1999	138.01
2000	142.03
2001	148.14
2002	153.61
2003	156.84
2004	153.89
2005	149.58
2006	158.06
2007	166.23
2008	173.52
2009	181.03
2010	186.49
2011	191.71
2012	197.33
2013	202.99
2014	209.09
2015	215.03
2016	221.08