condition mean min max ZT0-3 33.51845 33.51845 33.51845 ZT4-7 25.1464 25.1464 25.1464 ZT8-11 20.8012 20.8012 20.8012 ZT12-15 28.6552 28.6552 28.6552 ZT16-19 38.909850000000006 38.909850000000006 38.909850000000006 ZT20-23 38.412499999999994 38.412499999999994 38.412499999999994