What is the percentage change in net assets of post-employment benefit plans in 2019?
{"Net assets of post-employment benefit plans": {"NOTE": 24, "2019": 558, "2018": 331}, "Long-term notes and other receivables": {"NOTE": "", "2019": 142, "2018": 89}, "Derivative assets": {"NOTE": 26, "2019": 200, "2018": 68}, "Publicly-traded and privately-held investments": {"NOTE": 26, "2019": 129, "2018": 110}, "Investments(1)": {"NOTE": "", "2019": 128, "2018": 114}, "Other": {"NOTE": "", "2019": 117, "2018": 135}, "Total other non-current assets": {"NOTE": "", "2019": 1274, "2018": 847}}
net_assets_2019 = df["Net assets of post-employment benefit plans"]["2019"]
net_assets_2018 = df["Net assets of post-employment benefit plans"]["2018"]
answer = ( net_assets_2019 - net_assets_2018 ) / net_assets_2018 * 100.0