condition mean min max ZT0-3 11.203991666666667 9.244865 12.96231 ZT4-7 8.82167 8.82167 8.82167 ZT8-11 5.536 5.536 5.536 ZT12-15 2.7144225 1.83959 3.589255 ZT16-19 1.717395 1.717395 1.717395 ZT20-23 3.9479550000000003 3.9479550000000003 3.9479550000000003