Year	Number
1995	17.92878032
1996	17.9462099057
1997	17.9636394914
1998	17.9810690771
1999	17.9984986629
2000	18.0159282486
2001	18.0319816086
2002	18.0494111943
2003	18.0668407801
2004	18.0842703658
2005	18.1016999515
2006	18.1191295372
2007	16.9836573198
2008	19.7414415964
2009	20.8374333391
2010	20.7085842078
2011	21.7862262744
2012	22.8638683411
2013	23.9394460692
2014	23.9394460692
2015	23.9394460692
2016	23.9394460692
2017	23.9394460692
2018	23.9394460692
2019	23.9394460692
2020	23.9394460692