condition mean min max ZT0-3 40.409128525 33.61854386 47.19971319 ZT4-7 7.18767934525 6.2775526070000005 8.0978060835 ZT8-11 7.40569440325 5.7039990705 9.107389736 ZT12-15 7.28101070725 6.93289852 7.6291228945 ZT16-19 15.1407148575 11.20595224 19.075477475 ZT20-23 31.117175332500004 28.94492585 33.289424815000004