condition mean min max ZT0-3 12.80315 12.71285 12.893450000000001 ZT4-7 11.31875 11.31875 11.31875 ZT8-11 12.68795 12.68795 12.68795 ZT12-15 0 0 0 ZT16-19 15.72975 15.72975 15.72975 ZT20-23 13.3187 13.3187 13.3187