condition mean min max ZT0-3 2.00016 1.55975 2.32462 ZT4-7 2.08369 2.08369 2.08369 ZT8-11 4.836065 4.836065 4.836065 ZT12-15 4.7958725 4.06307 5.528675 ZT16-19 3.5061 3.5061 3.5061 ZT20-23 2.69319 2.69319 2.69319