condition mean min max ZT0-3 162.706225 162.706225 162.706225 ZT4-7 178.33108950000002 178.33108950000002 178.33108950000002 ZT8-11 223.021643 223.021643 223.021643 ZT12-15 213.3348165 213.3348165 213.3348165 ZT16-19 271.2985525 271.2985525 271.2985525 ZT20-23 228.80852950000002 228.80852950000002 228.80852950000002