condition mean min max ZT0-3 2.8825903333333334 1.059391 3.8029450000000002 ZT4-7 1.4764650000000001 1.4764650000000001 1.4764650000000001 ZT8-11 3.86665 3.86665 3.86665 ZT12-15 5.1007549999999995 3.858885 6.342625 ZT16-19 6.10979 6.10979 6.10979 ZT20-23 5.964255 5.964255 5.964255