condition mean min max ZT0-3 5.046306666666666 4.128385 6.600435 ZT4-7 5.58081 5.58081 5.58081 ZT8-11 5.313665 5.313665 5.313665 ZT12-15 5.7815075 5.75786 5.805155 ZT16-19 5.386955 5.386955 5.386955 ZT20-23 4.22386 4.22386 4.22386