Year Percent change (Units) 2015 7.221 2016 8.812 2017 1.096 2018 9.643 2019 4.905 2020 -33.957 2021 5.663 2022 25.772 2023 3.864 2024 6.956 2025 4.723 2026 3.559 2027 3.720 2028 3.633 2029 3.582