condition mean min max ZT0-3 11.6843 11.6843 11.6843 ZT4-7 9.75389 9.75389 9.75389 ZT8-11 8.521725 8.521725 8.521725 ZT12-15 9.665825 9.665825 9.665825 ZT16-19 9.729714999999999 9.729714999999999 9.729714999999999 ZT20-23 12.8401 12.8401 12.8401