Year	Number of
1990	12852.6
1991	13235.76
1992	13636.38
1993	14062.51
1994	14512.46
1995	14993.91
1996	15444.58
1997	15918.51
1998	16425.75
1999	16956.48
2000	17517.06
2001	18025.06
2002	18556.56
2003	19125.23
2004	19722.98
2005	20357.66
2006	21011.51
2007	21700.28
2008	22454.71
2009	23258.77
2010	24120.07
2011	25213.36
2012	26378.66
2013	27603.22
2014	28884.41
2015	30243.86
2016	31711.02