condition mean min max ZT0-3 174.717939 174.717939 174.717939 ZT4-7 194.618243 194.618243 194.618243 ZT8-11 164.37181950000002 164.37181950000002 164.37181950000002 ZT12-15 181.9350055 181.9350055 181.9350055 ZT16-19 206.22625599999998 206.22625599999998 206.22625599999998 ZT20-23 185.7475025 185.7475025 185.7475025