condition mean min max ZT0-3 1955.75 1955.75 1955.75 ZT4-7 1579.8 1579.8 1579.8 ZT8-11 1972.6 1972.6 1972.6 ZT12-15 2082.95 2082.95 2082.95 ZT16-19 1778.8000000000002 1778.8000000000002 1778.8000000000002 ZT20-23 1976.15 1976.15 1976.15