Year	Number of
1990	21004.85
1991	21628.48
1992	22160.93
1993	22702.23
1994	23254.24
1995	23785.88
1996	24473.71
1997	25303.64
1998	25894.52
1999	26544.59
2000	27209.02
2001	28169.88
2002	29232.26
2003	30334.24
2004	31604.73
2005	33264.92
2006	34203.51
2007	35385.25
2008	36569.65
2009	38202.66
2010	39875.25
2011	41587.7
2012	43395.81
2013	45181.14
2014	46746.16
2015	48537.1
2016	50410.18