condition mean min max ZT0-3 375.693595 375.693595 375.693595 ZT4-7 464.253098 464.253098 464.253098 ZT8-11 326.8177685 326.8177685 326.8177685 ZT12-15 278.1619535 278.1619535 278.1619535 ZT16-19 176.8655045 176.8655045 176.8655045 ZT20-23 128.4923065 128.4923065 128.4923065