Year	Number of
1990	17607.07
1991	18347.36
1992	19130.01
1993	19865.62
1994	20653.93
1995	21609.6
1996	22348.45
1997	22977.72
1998	23515.6
1999	23760.4
2000	24012.36
2001	23981.85
2002	23882.15
2003	23645.24
2004	23516.86
2005	23283.18
2006	23157.57
2007	23098.34
2008	23051.48
2009	22891.77
2010	22779
2011	22653.24
2012	22511.56
2013	22566.63
2014	23117.27
2015	23615.62
2016	24132.59