condition mean min max ZT0-3 318.842611 318.842611 318.842611 ZT4-7 246.5965735 246.5965735 246.5965735 ZT8-11 312.431051 312.431051 312.431051 ZT12-15 332.6484795 332.6484795 332.6484795 ZT16-19 427.71955049999997 427.71955049999997 427.71955049999997 ZT20-23 539.0284725 539.0284725 539.0284725