Year	Number
2011	3.1901620690800985
2012	5.430060829588329
2013	6.670159796712038
2014	6.425981285167674
2015	6.330014980154874
2016	5.336754044537078
2017	2.529578306468637
2018	4.696375162993049
2019	5.948638418096494
2020	6.773519814615386
2021	6.814639556229105
2022	5.863046573898925
2023	6.481048471372675