condition mean min max ZT0-3 15.663284 15.663284 15.663284 ZT4-7 14.086407999999999 14.086407999999999 14.086407999999999 ZT8-11 14.77411 14.77411 14.77411 ZT12-15 14.216855500000001 14.216855500000001 14.216855500000001 ZT16-19 15.5901005 15.5901005 15.5901005 ZT20-23 17.136291 17.136291 17.136291