condition mean min max ZT0-3 0.9571621666666666 0.7837 1.0504465 ZT4-7 0.258557 0.258557 0.258557 ZT8-11 3.93397 3.93397 3.93397 ZT12-15 6.5043975 6.0149 6.993895 ZT16-19 2.2566800000000002 2.2566800000000002 2.2566800000000002 ZT20-23 3.38359 3.38359 3.38359