condition mean min max ZT0-3 1.64053375125 1.6122444 1.6688231025 ZT4-7 3.675986415 2.854710721 4.497262109 ZT8-11 7.13372641675 6.1128957889999995 8.1545570445 ZT12-15 5.11025906825 4.479356192 5.7411619445 ZT16-19 3.0725427932500002 2.900336739 3.2447488475 ZT20-23 3.375633393 3.3667279015 3.3845388845000004