condition mean min max ZT0-3 5.76326 5.76326 5.76326 ZT4-7 4.0961549999999995 4.0961549999999995 4.0961549999999995 ZT8-11 4.948075 4.948075 4.948075 ZT12-15 5.545925 5.545925 5.545925 ZT16-19 8.52909 8.52909 8.52909 ZT20-23 6.3558699999999995 6.3558699999999995 6.3558699999999995