Year	Number of
1990	205.44
1991	207.75
1992	211.07
1993	214.84
1994	218.85
1995	223.16
1996	226.22
1997	229.56
1998	233.34
1999	237.52
2000	242.37
2001	247.31
2002	252.99
2003	259.36
2004	266.15
2005	273.57
2006	281.49
2007	289.56
2008	298.4
2009	307.85
2010	318.25
2011	328.38
2012	339.44
2013	350.97
2014	363.4
2015	376.81
2016	391.35