Year	Number
2011	2.84360194206238
2012	1.89573454856873
2013	1.42180097103119
2014	0.480769217014313
2015	0.476190477609634
2016	0
2017	0
2018	0
2019	0
2020	0.476190477609634
2021	0
2022	0