What was the change in the inventories between 2018 and 2019?
{"Deferred income tax assets: -- Loss/credit carryforwards": {"2019": 28391, "2018": 27915}, "Deferred income tax assets: -- Inventories ": {"2019": 16809, "2018": 6459}, "Deferred income tax assets: -- Accrued benefits": {"2019": 15834, "2018": 14459}, "Deferred income tax assets: -- Other ": {"2019": 3353, "2018": 3450}, "Deferred income tax assets: -- Total gross deferred income tax assets ": {"2019": 64387, "2018": 52283}, "Deferred income tax assets: -- Less valuation allowances ": {"2019": -29170, "2018": -28369}, "Deferred income tax assets: -- Deferred income tax assets": {"2019": 35217, "2018": 23914}, "Deferred income tax liabilities:     -- Property, plant and equipment": {"2019": 15621, "2018": 12530}, "Deferred income tax liabilities:     -- Tax on unremitted earnings ": {"2019": 5192, "2018": 14935}, "Deferred income tax liabilities:     -- Acceleration of revenue under Topic 606 ": {"2019": 6055, "2018": "\u2014"}, "Deferred income tax liabilities:     -- Deferred income tax liabilities ": {"2019": 26868, "2018": 27465}, "Deferred income tax liabilities:     --  Net deferred income tax assets/(liabilities)": {"2019": 8349, "2018": -3551}}
inventories_2019 = df["Deferred income tax assets: -- Inventories "]["2019"]
inventories_2018 = df["Deferred income tax assets: -- Inventories "]["2018"]
answer = inventories_2019 - inventories_2018