condition mean min max ZT0-3 8.1412875 6.925585 9.35699 ZT4-7 2.967525 2.967525 2.967525 ZT8-11 2.13166 2.13166 2.13166 ZT12-15 0 0 0 ZT16-19 6.227295 6.227295 6.227295 ZT20-23 7.031245 7.031245 7.031245