condition mean min max ZT0-3 7.445069999999999 6.514315 8.375824999999999 ZT4-7 3.589695 3.589695 3.589695 ZT8-11 3.93074 3.93074 3.93074 ZT12-15 0 0 0 ZT16-19 9.031725 9.031725 9.031725 ZT20-23 8.24079 8.24079 8.24079