time total_annual_NPP(PgC/yr) 2000.5 54.691705 2001.5 53.840830 2002.5 52.726950 2003.5 53.465397 2004.5 54.564763 2005.5 51.672067 2006.5 53.556794 2007.5 53.123160 2008.5 53.724899 2009.5 53.841365 2010.5 53.188167 2011.5 55.175548 2012.5 53.491369 2013.5 54.691705 2014.5 54.834212 2015.5 52.912872