condition mean min max ZT0-3 12.678329 12.678329 12.678329 ZT4-7 12.539873 12.539873 12.539873 ZT8-11 13.1378275 13.1378275 13.1378275 ZT12-15 11.6724485 11.6724485 11.6724485 ZT16-19 14.057269999999999 14.057269999999999 14.057269999999999 ZT20-23 12.4063325 12.4063325 12.4063325