condition mean min max ZT0-3 2.1314883333333334 1.2367149999999998 3.5839 ZT4-7 7.244674999999999 7.244674999999999 7.244674999999999 ZT8-11 2.198255 2.198255 2.198255 ZT12-15 1.8618575000000002 1.361205 2.3625100000000003 ZT16-19 1.47596 1.47596 1.47596 ZT20-23 1.221465 1.221465 1.221465