condition mean min max ZT0-3 15.505700000000001 15.505700000000001 15.505700000000001 ZT4-7 5.5497499999999995 5.5497499999999995 5.5497499999999995 ZT8-11 5.06829 5.06829 5.06829 ZT12-15 8.12101 8.12101 8.12101 ZT16-19 11.86635 11.86635 11.86635 ZT20-23 16.8273 16.8273 16.8273