condition mean min max ZT0-3 4.546355 4.29662 4.79609 ZT4-7 6.267944999999999 6.267944999999999 6.267944999999999 ZT8-11 3.5224 3.5224 3.5224 ZT12-15 0 0 0 ZT16-19 5.817955 5.817955 5.817955 ZT20-23 7.50334 7.50334 7.50334