What was the percentage change in the total assets between 2018 and 2019?
{"U.S.": {"April 26, 2019": 159, "April 27, 2018": 853}, "International": {"April 26, 2019": 3740, "April 27, 2018": 4538}, "Total": {"April 26, 2019": 3899, "April 27, 2018": 5391}}
total_assets_2019 = df["Total"]["April 26, 2019"]
total_assets_2018 = df["Total"]["April 27, 2018"]
answer = (total_assets_2019 - total_assets_2018) / total_assets_2018 * 100.0