Year	Number
1977	5.739565132130136
1978	5.922535360203415
1979	9.584495781484938
1980	9.034671081173467
1981	4.730438598581791
2005	18.04098926580545
2006	22.945746851106467
2007	26.366627124531092
2008	24.158185089236092
2009	26.007397790476652
2010	26.10546438366333
2011	36.65741327602472
2012	27.812350195025566
2013	24.418170817731628
2014	21.32968927659605
2015	22.831836429367193
2016	26.503022966979472
2017	24.250402615970945
2018	21.63592095370415
2019	17.885124724564776
2020	26.596803391134443
2021	18.444891500081702
2022	12.894781608757862