condition mean min max ZT0-3 3.0687925 2.85525 3.282335 ZT4-7 3.490825 3.490825 3.490825 ZT8-11 1.0352135 1.0352135 1.0352135 ZT12-15 0 0 0 ZT16-19 1.56921 1.56921 1.56921 ZT20-23 7.25551 7.25551 7.25551