Year	Number of
1990	206.98
1991	216.69
1992	228.06
1993	240.57
1994	253.52
1995	266.93
1996	274.23
1997	281.43
1998	288.5
1999	295.97
2000	304.52
2001	311.4
2002	319.25
2003	328.05
2004	337.5
2005	348.15
2006	355.67
2007	363.32
2008	372.41
2009	381.94
2010	392.35
2011	401.38
2012	411.16
2013	421.34
2014	432.42
2015	444.61
2016	458.45