Year	Number of
1990	205.67
1991	208.37
1992	215.13
1993	223.88
1994	227.94
1995	232.73
1996	232.38
1997	233.56
1998	236.73
1999	240.57
2000	244.33
2001	250.44
2002	256.37
2003	262.89
2004	269.84
2005	272.72
2006	275.06
2007	278
2008	281.59
2009	285.55
2010	289.89
2011	293.77
2012	299.09
2013	304.27
2014	312.31
2015	321.76
2016	330.95