condition mean min max ZT0-3 12.633775 10.911100000000001 14.35645 ZT4-7 21.27315 21.27315 21.27315 ZT8-11 17.47885 17.47885 17.47885 ZT12-15 0 0 0 ZT16-19 23.4481 23.4481 23.4481 ZT20-23 18.568350000000002 18.568350000000002 18.568350000000002