condition mean min max ZT0-3 21.73755 18.1362 25.3389 ZT4-7 39.73195 39.73195 39.73195 ZT8-11 26.002000000000002 26.002000000000002 26.002000000000002 ZT12-15 0 0 0 ZT16-19 26.409399999999998 26.409399999999998 26.409399999999998 ZT20-23 32.6453 32.6453 32.6453