condition mean min max ZT0-3 5.709495 5.044825 6.374165 ZT4-7 4.33169 4.33169 4.33169 ZT8-11 3.14672 3.14672 3.14672 ZT12-15 0 0 0 ZT16-19 3.983785 3.983785 3.983785 ZT20-23 6.36955 6.36955 6.36955