condition mean min max ZT0-3 5.300155 4.6377749999999995 5.962535 ZT4-7 6.23326 6.23326 6.23326 ZT8-11 5.11318 5.11318 5.11318 ZT12-15 0 0 0 ZT16-19 5.50213 5.50213 5.50213 ZT20-23 5.21673 5.21673 5.21673