condition mean min max ZT0-3 2.5991475 2.40921 2.789085 ZT4-7 1.264292 1.264292 1.264292 ZT8-11 2.423445 2.423445 2.423445 ZT12-15 0 0 0 ZT16-19 2.497655 2.497655 2.497655 ZT20-23 2.19074 2.19074 2.19074