condition mean min max ZT0-3 5.995975 5.31599 6.67596 ZT4-7 4.622405 4.622405 4.622405 ZT8-11 2.515835 2.515835 2.515835 ZT12-15 0 0 0 ZT16-19 4.190165 4.190165 4.190165 ZT20-23 5.016405 5.016405 5.016405