condition mean min max ZT0-3 291.693595 291.693595 291.693595 ZT4-7 239.1988485 239.1988485 239.1988485 ZT8-11 233.5150185 233.5150185 233.5150185 ZT12-15 292.986502 292.986502 292.986502 ZT16-19 329.579811 329.579811 329.579811 ZT20-23 297.178927 297.178927 297.178927