Year	Number
1996	3.22580647468567
1998	3.74331545829773
2000	3.19148945808411
2002	9.5238094329834
2003	9.5238094329834
2004	14.2857141494751
2005	15.6097564697266
2006	19.5121955871582
2007	19.4174766540527
2008	17.9611644744873
2009	18.1818180084229
2010	17.1428565979004
2011	18.9573459625244
2012	21.8009471893311
2013	26.5402851104736
2014	29.8076915740967
2015	28.0952377319336
2016	30
2017	22.380952835083
2018	26.1904754638672
2019	28.0952377319336
2020	28.5714282989502
2021	27.619047164917
2022	25.4716987609863