condition mean min max ZT0-3 17.34905 15.05555 20.11255 ZT4-7 24.1241 24.1241 24.1241 ZT8-11 16.13715 16.13715 16.13715 ZT12-15 19.3534 18.088 20.6188 ZT16-19 21.7579 21.7579 21.7579 ZT20-23 13.68735 13.68735 13.68735