condition mean min max ZT0-3 6.25319 6.25319 6.25319 ZT4-7 4.927245 4.927245 4.927245 ZT8-11 5.602735 5.602735 5.602735 ZT12-15 5.887925 5.887925 5.887925 ZT16-19 10.14916 10.14916 10.14916 ZT20-23 7.42764 7.42764 7.42764