condition mean min max ZT0-3 7.347671666666667 2.20403 12.681185 ZT4-7 4.15613 4.15613 4.15613 ZT8-11 0.0 0.0 0.0 ZT12-15 4.335777500000001 2.786805 5.88475 ZT16-19 6.65202 6.65202 6.65202 ZT20-23 4.323695 4.323695 4.323695