condition mean min max ZT0-3 4.1176775 3.34422 4.891135 ZT4-7 1.8924230000000002 1.8924230000000002 1.8924230000000002 ZT8-11 2.55293 2.55293 2.55293 ZT12-15 0 0 0 ZT16-19 3.970675 3.970675 3.970675 ZT20-23 1.68116 1.68116 1.68116