condition mean min max ZT0-3 0.246886 0.246886 0.246886 ZT4-7 0.23026 0.23026 0.23026 ZT8-11 0.296077 0.296077 0.296077 ZT12-15 0.2607105 0.2607105 0.2607105 ZT16-19 0.5861905000000001 0.5861905000000001 0.5861905000000001 ZT20-23 0.37657700000000005 0.37657700000000005 0.37657700000000005