Year	Number of
1990	153.77
1991	159.53
1992	165.66
1993	171.45
1994	177.52
1995	183.94
1996	190.19
1997	196.93
1998	203.86
1999	211.22
2000	219.07
2001	224.04
2002	229.75
2003	236.19
2004	242.82
2005	249.55
2006	259.16
2007	268.95
2008	280.06
2009	291.95
2010	304.86
2011	312.43
2012	320.95
2013	330.16
2014	339.86
2015	349.89
2016	360.01