Year	Number of
1990	15021.2
1991	16015.61
1992	17076.74
1993	18197.05
1994	19415.65
1995	20731.07
1996	22572.94
1997	24621.73
1998	26869.19
1999	29293.57
2000	32061.05
2001	34999.67
2002	38138.04
2003	41475.47
2004	45061.32
2005	48853.64
2006	51557.51
2007	54509.47
2008	57632.99
2009	60829.54
2010	64079.31
2011	65515.9
2012	67067.6
2013	68739.7
2014	70345.36
2015	72042.68
2016	73795.44