condition mean min max ZT0-3 1580.191495 1580.191495 1580.191495 ZT4-7 1536.6754685 1536.6754685 1536.6754685 ZT8-11 1426.9324145 1426.9324145 1426.9324145 ZT12-15 1500.1403735 1500.1403735 1500.1403735 ZT16-19 1783.811847 1783.811847 1783.811847 ZT20-23 1981.040973 1981.040973 1981.040973