condition mean min max ZT0-3 10.586879 10.586879 10.586879 ZT4-7 11.7351685 11.7351685 11.7351685 ZT8-11 13.785656500000002 13.785656500000002 13.785656500000002 ZT12-15 12.3913195 12.3913195 12.3913195 ZT16-19 12.4204 12.4204 12.4204 ZT20-23 12.477169 12.477169 12.477169