condition mean min max ZT0-3 6.6754425 5.432515 7.9183699999999995 ZT4-7 9.337545 9.337545 9.337545 ZT8-11 11.122 11.122 11.122 ZT12-15 0 0 0 ZT16-19 10.802095 10.802095 10.802095 ZT20-23 8.019465 8.019465 8.019465