condition mean min max ZT0-3 1.952025 1.952025 1.952025 ZT4-7 1.1817915 1.1817915 1.1817915 ZT8-11 1.15544 1.15544 1.15544 ZT12-15 3.3524450000000003 3.3524450000000003 3.3524450000000003 ZT16-19 3.81963 3.81963 3.81963 ZT20-23 2.68568 2.68568 2.68568