condition mean min max ZT0-3 17.9465 13.13575 21.42225 ZT4-7 10.287154999999998 10.287154999999998 10.287154999999998 ZT8-11 13.6586 13.6586 13.6586 ZT12-15 12.1704575 11.340715 13.0002 ZT16-19 11.9619 11.9619 11.9619 ZT20-23 20.3559 20.3559 20.3559