Year	Number of
1990	21268.72
1991	22730.51
1992	24301.89
1993	25665.17
1994	27110.27
1995	28667.28
1996	28287.95
1997	28000.17
1998	27655.25
1999	27190.56
2000	26689.27
2001	27309.53
2002	27905.94
2003	28484.15
2004	28951.78
2005	29530.14
2006	29763.36
2007	30058.54
2008	30262.95
2009	30481.18
2010	30810.06
2011	31106.65
2012	31490.05
2013	31842.52
2014	32235.01
2015	32990.27
2016	33863.73