condition mean min max ZT0-3 6.69763 6.69763 6.69763 ZT4-7 6.215945 6.215945 6.215945 ZT8-11 5.543760000000001 5.543760000000001 5.543760000000001 ZT12-15 7.5780899999999995 7.5780899999999995 7.5780899999999995 ZT16-19 9.788415 9.788415 9.788415 ZT20-23 9.074015 9.074015 9.074015