Year	Number of
1990	214.87
1991	224.4
1992	209
1993	196.9
1994	185.58
1995	173.97
1996	179.36
1997	182.2
1998	185.46
1999	193.12
2000	200.78
2001	211.96
2002	222.63
2003	231.54
2004	243.06
2005	255.67
2006	269.15
2007	283.29
2008	299.21
2009	316.42
2010	334.07
2011	349.25
2012	366.37
2013	384.75
2014	403.54
2015	423.55
2016	440.04