condition mean min max ZT0-3 10.625062499999999 9.52714 11.722985 ZT4-7 12.0414 12.0414 12.0414 ZT8-11 15.447500000000002 15.447500000000002 15.447500000000002 ZT12-15 0 0 0 ZT16-19 14.8167 14.8167 14.8167 ZT20-23 14.161750000000001 14.161750000000001 14.161750000000001