condition mean min max ZT0-3 0.23633833333333332 0.1861275 0.309569 ZT4-7 1.1300750000000002 1.1300750000000002 1.1300750000000002 ZT8-11 3.47225 3.47225 3.47225 ZT12-15 3.299615 2.411045 4.188185 ZT16-19 1.201193 1.201193 1.201193 ZT20-23 1.015917 1.015917 1.015917