Year	Number of
1990	15228.22
1991	16385.6
1992	17668.74
1993	18821.52
1994	20036.01
1995	21375.19
1996	21869.11
1997	22455.18
1998	22972.38
1999	23347.79
2000	23682.15
2001	24809.08
2002	25941.52
2003	27032.36
2004	28018.52
2005	29145.02
2006	30253.65
2007	31473.15
2008	32621.77
2009	33848.52
2010	35285.31
2011	36008.57
2012	36906.26
2013	37806.24
2014	38817.86
2015	40307.77
2016	41994.29