condition mean min max ZT0-3 11.074471 11.074471 11.074471 ZT4-7 12.943557 12.943557 12.943557 ZT8-11 11.475074 11.475074 11.475074 ZT12-15 13.023201499999999 13.023201499999999 13.023201499999999 ZT16-19 12.2889335 12.2889335 12.2889335 ZT20-23 11.487773 11.487773 11.487773