What was the change in the asset impairment charges from 2018 to 2019?
{"Asset impairment charges": {"2019": 10837, "2018": 58166, "2017": 0}, "Goodwill impairment charge": {"2019": 25700, "2018": 13466, "2017": 0}, "Impairment of long-term investments": {"2019": 651, "2018": 15487, "2017": 165290}}
asset_impairment_charges_2019 = df["Asset impairment charges"]["2019"]
asset_impairment_charges_2018 = df["Asset impairment charges"]["2018"]
answer = asset_impairment_charges_2019 - asset_impairment_charges_2018