condition mean min max ZT0-3 5.12327 5.12327 5.12327 ZT4-7 3.5435800000000004 3.5435800000000004 3.5435800000000004 ZT8-11 5.177275 5.177275 5.177275 ZT12-15 6.436545 6.436545 6.436545 ZT16-19 6.8628100000000005 6.8628100000000005 6.8628100000000005 ZT20-23 7.412176666666666 7.412176666666666 7.412176666666666