Year Percent change (Units) 2012 1.200 2013 5.655 2014 2.747 2015 4.589 2016 -1.275 2017 9.500 2018 2.994 2019 3.627 2020 -2.560 2021 3.308 2022 2.433 2023 2.800 2024 3.700 2025 3.900 2026 4.000 2027 4.100 2028 4.300 2029 4.500