condition mean min max ZT0-3 3.80641 3.80641 3.80641 ZT4-7 2.72069 2.72069 2.72069 ZT8-11 4.81138 4.81138 4.81138 ZT12-15 6.133635 6.133635 6.133635 ZT16-19 6.054 6.054 6.054 ZT20-23 5.21927 5.21927 5.21927