condition mean min max ZT0-3 8.76026 8.76026 8.76026 ZT4-7 15.491050000000001 15.491050000000001 15.491050000000001 ZT8-11 6.524085 6.524085 6.524085 ZT12-15 4.3290500000000005 4.3290500000000005 4.3290500000000005 ZT16-19 6.96159 6.96159 6.96159 ZT20-23 7.18943 7.18943 7.18943