Year % 2012 3.11552650685681 2013 2.82286034908823 2014 2.832816419541 2015 3.021368902847 2016 3.13539021739587 2017 3.01513440026541 2018 2.84180413882467 2019 2.28627227440686 2020 2.07201818483434 2021 1.89364268200428 2022 1.65068335655342 2023 1.54305460414344