condition mean min max ZT0-3 2.3487625000000003 1.586405 3.11112 ZT4-7 2.209105 2.209105 2.209105 ZT8-11 4.44588 4.44588 4.44588 ZT12-15 0 0 0 ZT16-19 4.36559 4.36559 4.36559 ZT20-23 6.266249999999999 6.266249999999999 6.266249999999999