condition mean min max ZT0-3 8.080369999999998 7.40072 8.760019999999999 ZT4-7 8.015525 8.015525 8.015525 ZT8-11 4.098475 4.098475 4.098475 ZT12-15 0 0 0 ZT16-19 8.486995 8.486995 8.486995 ZT20-23 8.410655 8.410655 8.410655