condition mean min max ZT0-3 0.8985621666666667 0.766376 1.101739 ZT4-7 0.8223735 0.8223735 0.8223735 ZT8-11 1.13931 1.13931 1.13931 ZT12-15 1.5697575000000001 1.42805 1.711465 ZT16-19 0.6072125 0.6072125 0.6072125 ZT20-23 2.331115 2.331115 2.331115