What is the change in the plant value between 2018 and 2019?
{"Land": {"2019": 730, "2018": 585, "Estimated Useful Lives": ""}, "Furniture and fixtures": {"2019": 476, "2018": 430, "Estimated Useful Lives": 5}, "Plant": {"2019": 9667, "2018": 8613, "Estimated Useful Lives": 20}, "Computer and software": {"2019": 1317, "2018": 1295, "Estimated Useful Lives": 3}, "Leasehold improvements": {"2019": 2019, "2018": 681, "Estimated Useful Lives": 4}, "Machinery and equipment": {"2019": 16864, "2018": 13528, "Estimated Useful Lives": 5}, "Property and equipment, cost": {"2019": 31073, "2018": 25132, "Estimated Useful Lives": ""}, "Less accumulated depreciation": {"2019": 11996, "2018": 10122, "Estimated Useful Lives": ""}, "Property and equipment, net": {"2019": 19077, "2018": 15010, "Estimated Useful Lives": ""}}
plant_2019 = df["Plant"]["2019"]
plant_2018 = df["Plant"]["2018"]
answer = plant_2019 - plant_2018