Year Percent change (Units) 2015 13.286 2016 15.487 2017 -0.985 2018 -1.992 2019 -0.076 2020 -21.853 2021 3.303 2022 15.800 2023 23.226 2024 4.317 2025 4.667 2026 4.205 2027 3.706 2028 3.387 2029 3.304