condition mean min max ZT0-3 6.03734 6.03734 6.03734 ZT4-7 4.40934 4.40934 4.40934 ZT8-11 4.6931899999999995 4.6931899999999995 4.6931899999999995 ZT12-15 4.77308 4.77308 4.77308 ZT16-19 6.615349999999999 6.615349999999999 6.615349999999999 ZT20-23 6.12762 6.12762 6.12762