condition mean min max ZT0-3 12.710356 12.710356 12.710356 ZT4-7 13.934819000000001 13.934819000000001 13.934819000000001 ZT8-11 13.244785 13.244785 13.244785 ZT12-15 12.377645999999999 12.377645999999999 12.377645999999999 ZT16-19 13.258736500000001 13.258736500000001 13.258736500000001 ZT20-23 13.3681825 13.3681825 13.3681825