| Year | Value | | 2022 | 84.736659359634 | | 2021 | 81.05634208196 | | 2020 | 79.172743912358 | | 2019 | 77.875358961123 | | 2018 | 75.914688328506 | | 2017 | 77.639942688344 | | 2016 | 77.601321857003 | | 2015 | 80.258223965421 | | 2014 | 79.464116915399 | | 2013 | 82.422518059813 | | 2012 | 80.765342151698 | | 2011 | 82.751559242302 |
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