What is the percentage change in the company's goodwill between 2018 and 2019?
{"Consolidated Balance Sheet Data (2) (3): -- Total cash, cash equivalents, and marketable securities": {"2019": 68363, "2018": 207423, "2017": 223748, "2016": 133761, "2015": 219078}, "Consolidated Balance Sheet Data (2) (3): -- Goodwill": {"2019": 79039, "2018": 72858, "2017": 72952, "2016": 73164, "2015": 46776}, "Consolidated Balance Sheet Data (2) (3): -- Total assets": {"2019": 984812, "2018": 982553, "2017": 1012753, "2016": 867135, "2015": 627758}, "Consolidated Balance Sheet Data (2) (3): -- Total stockholders equity": {"2019": 539010, "2018": 621531, "2017": 655870, "2016": 548940, "2015": 322859}}
goodwill_2019 = df["Consolidated Balance Sheet Data (2) (3): -- Goodwill"]["2019"]
goodwill_2018 = df["Consolidated Balance Sheet Data (2) (3): -- Goodwill"]["2018"]
answer = (goodwill_2019 - goodwill_2018) / goodwill_2018 * 100.0