condition mean min max ZT0-3 3.4659821666666666 1.0881665 5.95599 ZT4-7 3.4886749999999997 3.4886749999999997 3.4886749999999997 ZT8-11 3.080125 3.080125 3.080125 ZT12-15 5.58043 4.748735 6.412125 ZT16-19 4.619775000000001 4.619775000000001 4.619775000000001 ZT20-23 4.9816 4.9816 4.9816