condition mean min max ZT0-3 8.282312 8.282312 8.282312 ZT4-7 7.641424000000001 7.641424000000001 7.641424000000001 ZT8-11 8.282811500000001 8.282811500000001 8.282811500000001 ZT12-15 7.471891 7.471891 7.471891 ZT16-19 7.709035 7.709035 7.709035 ZT20-23 8.556620500000001 8.556620500000001 8.556620500000001