condition mean min max ZT0-3 13.291517 13.291517 13.291517 ZT4-7 12.946526500000001 12.946526500000001 12.946526500000001 ZT8-11 10.1803195 10.1803195 10.1803195 ZT12-15 9.7837715 9.7837715 9.7837715 ZT16-19 9.084638 9.084638 9.084638 ZT20-23 8.5451165 8.5451165 8.5451165