Year	Number of
1990	219.81
1991	217.02
1992	213.91
1993	210.98
1994	207.71
1995	204.25
1996	211.15
1997	217.9
1998	224.36
1999	230.72
2000	237.01
2001	248.04
2002	259.1
2003	269.84
2004	280.64
2005	291.72
2006	288.77
2007	285.93
2008	283.67
2009	281.78
2010	280.4
2011	281.47
2012	283.38
2013	285.45
2014	288.09
2015	291.24
2016	295.66