condition mean min max ZT0-3 6.0902899999999995 6.0902899999999995 6.0902899999999995 ZT4-7 4.520265 4.520265 4.520265 ZT8-11 4.604705 4.604705 4.604705 ZT12-15 4.740945 4.740945 4.740945 ZT16-19 7.571019999999999 7.571019999999999 7.571019999999999 ZT20-23 6.406495 6.406495 6.406495