condition mean min max ZT0-3 0.870296 0.870296 0.870296 ZT4-7 2.509245 2.509245 2.509245 ZT8-11 2.044115 2.044115 2.044115 ZT12-15 1.1784910000000002 1.1784910000000002 1.1784910000000002 ZT16-19 0.9992415000000001 0.9992415000000001 0.9992415000000001 ZT20-23 1.051661 1.051661 1.051661