condition mean min max ZT0-3 2.45397 1.533345 3.270365 ZT4-7 1.676354 1.676354 1.676354 ZT8-11 3.838045 3.838045 3.838045 ZT12-15 1.97107 1.13532 2.80682 ZT16-19 2.92886 2.92886 2.92886 ZT20-23 1.849425 1.849425 1.849425