condition mean min max ZT0-3 17.9457 16.6265 19.264899999999997 ZT4-7 16.3776 16.3776 16.3776 ZT8-11 12.1629 12.1629 12.1629 ZT12-15 0 0 0 ZT16-19 15.94115 15.94115 15.94115 ZT20-23 21.899949999999997 21.899949999999997 21.899949999999997