condition mean min max ZT0-3 4.0526325 3.340245 4.76502 ZT4-7 7.50132 7.50132 7.50132 ZT8-11 10.8451 10.8451 10.8451 ZT12-15 0 0 0 ZT16-19 5.64673 5.64673 5.64673 ZT20-23 6.586145 6.586145 6.586145