condition mean min max ZT0-3 270.33299999999997 270.33299999999997 270.33299999999997 ZT4-7 120.16499999999999 120.16499999999999 120.16499999999999 ZT8-11 77.62700000000001 77.62700000000001 77.62700000000001 ZT12-15 168.48000000000002 168.48000000000002 168.48000000000002 ZT16-19 215.7673333333333 215.7673333333333 215.7673333333333 ZT20-23 309.31 309.31 309.31