What was the percentage change in additions between 2018 and 2019?
{"Balance at beginning of period": {"April 26, 2019": 3363, "April 27, 2018": 3213}, "Additions": {"April 26, 2019": 2763, "April 27, 2018": 2566}, "Revenue recognized during the period": {"April 26, 2019": -2458, "April 27, 2018": -2416}, "Balance at end of period": {"April 26, 2019": 3668, "April 27, 2018": 3363}}
additions_2019 = df["Additions"]["April 26, 2019"]
additions_2018 = df["Additions"]["April 27, 2018"]
answer = ( additions_2019 - additions_2018 ) / additions_2018 * 100.0