How much were the top 3 components of property and equipment as a % of the total at cost, property and equipment for 2019?
{"(In millions) -- June 30,": {"2019": 2019, "2018": 2018}, "(In millions) -- Land": {"2019": 1540, "2018": 1254}, "(In millions) -- Buildings and improvements": {"2019": 26288, "2018": 20604}, "(In millions) -- Leasehold improvements": {"2019": 5316, "2018": 4735}, "(In millions) -- Computer equipment and software": {"2019": 33823, "2018": 27633}, "(In millions) -- Furniture and equipment": {"2019": 4840, "2018": 4457}, "(In millions) -- Total, at cost": {"2019": 71807, "2018": 58683}, "(In millions) -- Accumulated depreciation": {"2019": -35330, "2018": -29223}, "(In millions) -- Total, net": {"2019": 36477, "2018": 29460}}
buildings_and_improvements_2019 = df["(In millions) -- Buildings and improvements"]["2019"]
computer_equipment_and_software_2019 = df["(In millions) -- Computer equipment and software"]["2019"]
leasehold_improvements_2019 = df["(In millions) -- Leasehold improvements"]["2019"]
total_at_cost_2019 = df["(In millions) -- Total, at cost"]["2019"]
answer = ( buildings_and_improvements_2019 + computer_equipment_and_software_2019 + leasehold_improvements_2019 ) / total_at_cost_2019 * 100.0