condition mean min max ZT0-3 1.0234685 1.0234685 1.0234685 ZT4-7 0.841271 0.841271 0.841271 ZT8-11 1.333015 1.333015 1.333015 ZT12-15 2.5905500000000004 2.5905500000000004 2.5905500000000004 ZT16-19 1.47222 1.47222 1.47222 ZT20-23 0.911814 0.911814 0.911814