condition mean min max ZT0-3 10.586879 10.586879 10.586879 ZT4-7 10.3737285 10.3737285 10.3737285 ZT8-11 10.301184500000002 10.301184500000002 10.301184500000002 ZT12-15 9.49394 9.49394 9.49394 ZT16-19 9.428889999999999 9.428889999999999 9.428889999999999 ZT20-23 9.9723805 9.9723805 9.9723805