condition mean min max ZT0-3 3.8215500000000002 3.8215500000000002 3.8215500000000002 ZT4-7 3.316895 3.316895 3.316895 ZT8-11 5.02304 5.02304 5.02304 ZT12-15 4.5538 4.5538 4.5538 ZT16-19 6.985995 6.985995 6.985995 ZT20-23 3.945685 3.945685 3.945685