condition mean min max ZT0-3 5.7835475 5.67964 5.887455 ZT4-7 5.07233 5.07233 5.07233 ZT8-11 5.639545 5.639545 5.639545 ZT12-15 0 0 0 ZT16-19 7.40798 7.40798 7.40798 ZT20-23 7.56886 7.56886 7.56886