condition mean min max ZT0-3 8.816976 8.816976 8.816976 ZT4-7 10.2338135 10.2338135 10.2338135 ZT8-11 9.741924000000001 9.741924000000001 9.741924000000001 ZT12-15 8.8175445 8.8175445 8.8175445 ZT16-19 9.936524 9.936524 9.936524 ZT20-23 10.365302499999999 10.365302499999999 10.365302499999999