condition mean min max ZT0-3 4.8802475 4.749700000000001 5.010795 ZT4-7 3.71328 3.71328 3.71328 ZT8-11 7.183965000000001 7.183965000000001 7.183965000000001 ZT12-15 0 0 0 ZT16-19 7.431125 7.431125 7.431125 ZT20-23 7.498125 7.498125 7.498125