condition mean min max ZT0-3 6.8072 6.289565 7.324835 ZT4-7 4.166775 4.166775 4.166775 ZT8-11 4.63269 4.63269 4.63269 ZT12-15 0 0 0 ZT16-19 6.88192 6.88192 6.88192 ZT20-23 5.99527 5.99527 5.99527