condition mean min max ZT0-3 1.815375 1.815375 1.815375 ZT4-7 0.787449 0.787449 0.787449 ZT8-11 1.8507 1.8507 1.8507 ZT12-15 1.8466749999999998 1.8466749999999998 1.8466749999999998 ZT16-19 3.602225 3.602225 3.602225 ZT20-23 1.966615 1.966615 1.966615