condition mean min max ZT0-3 13.563558 13.563558 13.563558 ZT4-7 16.016259 16.016259 16.016259 ZT8-11 12.6142965 12.6142965 12.6142965 ZT12-15 12.924713 12.924713 12.924713 ZT16-19 13.658504 13.658504 13.658504 ZT20-23 14.9847985 14.9847985 14.9847985