Year Percent change (Units) 1998 -96.500 1999 1812.100 2000 -0.091 2001 5.498 2002 6.074 2003 -13.811 2004 135.142 2005 -18.332 2006 40.582 2007 -6.706 2008 28.472 2009 -13.929 2010 -18.085 2011 62.574 2012 34.398 2013 -7.693 2014 69.545 2015 16.461 2016 -14.765 2017 -27.612 2018 -7.517 2019 -5.655 2020 22.428 2021 5.080 2022 -0.998 2023 37.134 2024 4.844 2025 7.428 2026 5.945 2027 4.179 2028 5.040 2029 0.422