Year	Number of
1990	131.48
1991	131.58
1992	131.4
1993	131.29
1994	131.71
1995	132.96
1996	135.06
1997	138.29
1998	142.59
1999	147.29
2000	152.2
2001	155.18
2002	158.43
2003	161.84
2004	165.35
2005	169.01
2006	172.1
2007	175.01
2008	177.94
2009	181.12
2010	184.7
2011	187.87
2012	191.51
2013	195.38
2014	199.52
2015	203.92
2016	209.58