Year % 2010 7.68539480893566 2011 7.5351167253222 2012 7.67717422206232 2013 7.48548984386741 2014 7.1451600357314 2015 7.03798113217368 2016 7.32457471338062 2017 6.63942230277621 2018 6.7287898522671 2019 6.87991830877405 2020 6.81023539088295 2021 6.73751772733858