condition mean min max ZT0-3 2.805245 2.32651 3.28398 ZT4-7 1.497865 1.497865 1.497865 ZT8-11 2.437365 2.437365 2.437365 ZT12-15 0 0 0 ZT16-19 3.553115 3.553115 3.553115 ZT20-23 2.8634250000000003 2.8634250000000003 2.8634250000000003