Year	Number
1996	18.8172035217285
1998	21.3903751373291
2000	21.2765960693359
2002	23.8095245361328
2003	30.1587295532227
2004	23.645320892334
2005	18.0487804412842
2006	20.9756088256836
2007	23.7864074707031
2008	23.3009700775146
2009	24.4019145965576
2010	21.4285717010498
2011	18.9573459625244
2012	15.1658763885498
2013	16.1137447357178
2014	15.384614944458
2015	20
2016	14.7619047164917
2017	14.7619047164917
2018	16.1904754638672
2019	16.6666660308838
2020	19.5238094329834
2021	20.4761905670166
2022	20.7547168731689