What was the percentage change in franking credits between 2018 and 2019?
{"": {"2019": 0, "2018": 0}, "Dividends paid during the year (net of dividend re-investment) -- 4 cent per share final dividend paid 27 September 2018  fully franked1": {"2019": 7319, "2018": ""}, "Dividends paid during the year (net of dividend re-investment) -- 3 cent per share final dividend paid 30 September 2017  fully franked": {"2019": "", "2018": 5175}, "Dividends paid during the year (net of dividend re-investment) -- 3 cent per share interim dividend paid 29 March 2019  fully franked": {"2019": 5318, "2018": ""}, "Dividends paid during the year (net of dividend re-investment) -- 3 cent per share interim dividend paid 29 March 2018  fully franked": {"2019": "", "2018": 5217}, "Dividends paid during the year (net of dividend re-investment) -- ": {"2019": 12637, "2018": 10392}, "Dividends paid during the year (net of dividend re-investment) -- Proposed dividend not recognised at the end of the year": {"2019": 5922, "2018": 7865}, "Dividends franking account -- 30% franking credits, on a tax paid basis, are available to shareholders of Hansen Technologies Ltd for subsequent financial years": {"2019": 1586, "2018": 3125}}
franking_2019 = df["Dividends franking account -- 30% franking credits, on a tax paid basis, are available to shareholders of Hansen Technologies Ltd for subsequent financial years"]["2019"]
franking_2018 = df["Dividends franking account -- 30% franking credits, on a tax paid basis, are available to shareholders of Hansen Technologies Ltd for subsequent financial years"]["2018"]
answer = (franking_2019 - franking_2018) / franking_2018 * 100.0