Year Percent change (Units) 2013 6.051 2014 -0.307 2015 -8.175 2016 -10.252 2017 3.956 2018 0.276 2019 -3.115 2020 -12.218 2021 17.597 2022 12.622 2023 3.348 2024 6.629 2025 4.852 2026 4.667 2027 4.209 2028 4.045 2029 4.408