condition mean min max ZT0-3 235.982418 235.982418 235.982418 ZT4-7 314.262951 314.262951 314.262951 ZT8-11 325.3899505 325.3899505 325.3899505 ZT12-15 362.41209849999996 362.41209849999996 362.41209849999996 ZT16-19 264.51647149999997 264.51647149999997 264.51647149999997 ZT20-23 169.31457650000002 169.31457650000002 169.31457650000002