condition mean min max ZT0-3 24.75665 24.75665 24.75665 ZT4-7 17.6342 17.6342 17.6342 ZT8-11 16.5003 16.5003 16.5003 ZT12-15 21.73975 21.73975 21.73975 ZT16-19 26.8003 26.8003 26.8003 ZT20-23 28.3345 28.3345 28.3345