Year	Number of
1990	88.24
1991	94.67
1992	101.87
1993	109.89
1994	118.74
1995	128.59
1996	137.23
1997	146.65
1998	156.97
1999	168.11
2000	180.17
2001	190.09
2002	200.55
2003	211.85
2004	223.78
2005	236.45
2006	244.62
2007	253.26
2008	262.95
2009	273.27
2010	284.32
2011	293.32
2012	303.1
2013	313.47
2014	324.4
2015	335.87
2016	349.63