condition mean min max ZT0-3 8.998757 8.998757 8.998757 ZT4-7 11.6227995 11.6227995 11.6227995 ZT8-11 11.1627965 11.1627965 11.1627965 ZT12-15 10.8802855 10.8802855 10.8802855 ZT16-19 10.5938485 10.5938485 10.5938485 ZT20-23 9.9370165 9.9370165 9.9370165