condition mean min max ZT0-3 168.558197 168.558197 168.558197 ZT4-7 158.41722299999998 158.41722299999998 158.41722299999998 ZT8-11 210.2142665 210.2142665 210.2142665 ZT12-15 215.474333 215.474333 215.474333 ZT16-19 323.574539 323.574539 323.574539 ZT20-23 274.1712735 274.1712735 274.1712735