condition mean min max ZT0-3 23.524964 23.524964 23.524964 ZT4-7 13.9890525 13.9890525 13.9890525 ZT8-11 11.283355499999999 11.283355499999999 11.283355499999999 ZT12-15 10.62575 10.62575 10.62575 ZT16-19 12.008583 12.008583 12.008583 ZT20-23 11.578617 11.578617 11.578617