condition mean min max ZT0-3 2.798715 2.798715 2.798715 ZT4-7 0.6509834999999999 0.6509834999999999 0.6509834999999999 ZT8-11 4.818715 4.818715 4.818715 ZT12-15 8.755115 8.755115 8.755115 ZT16-19 4.890029999999999 4.890029999999999 4.890029999999999 ZT20-23 4.39132 4.39132 4.39132