condition mean min max ZT0-3 17.56935 14.997 20.1417 ZT4-7 16.2728 16.2728 16.2728 ZT8-11 28.4715 28.4715 28.4715 ZT12-15 0 0 0 ZT16-19 32.094049999999996 32.094049999999996 32.094049999999996 ZT20-23 31.018500000000003 31.018500000000003 31.018500000000003