condition mean min max ZT0-3 2.58616 2.58616 2.58616 ZT4-7 2.068275 2.068275 2.068275 ZT8-11 2.8931649999999998 2.8931649999999998 2.8931649999999998 ZT12-15 2.86117 2.86117 2.86117 ZT16-19 4.033440000000001 4.033440000000001 4.033440000000001 ZT20-23 2.8570900000000004 2.8570900000000004 2.8570900000000004