Year	Number
1996	16.5
1998	17.9104480743408
2000	14.4278602600098
2002	7.96019887924194
2003	7.96019887924194
2004	5.28846168518066
2005	6.25
2006	22.115385055542
2007	25
2008	25.480770111084
2009	24.6445503234863
2010	22.748815536499
2011	20.1877937316895
2012	20.1877937316895
2013	22.0657272338867
2014	21.1822662353516
2015	20.6896553039551
2016	22.1674880981445
2017	22.1674880981445
2018	21.3592224121094
2019	22.2222213745117
2020	20.2898559570313
2021	17.3913040161133
2022	10.1449279785156