condition mean min max ZT0-3 12.37915 12.37915 12.37915 ZT4-7 9.287485 9.287485 9.287485 ZT8-11 8.89357 8.89357 8.89357 ZT12-15 9.28551 9.28551 9.28551 ZT16-19 11.57265 11.57265 11.57265 ZT20-23 11.65485 11.65485 11.65485