condition mean min max ZT0-3 17.33335 17.33335 17.33335 ZT4-7 8.61853 8.61853 8.61853 ZT8-11 12.506599999999999 12.506599999999999 12.506599999999999 ZT12-15 18.9149 18.9149 18.9149 ZT16-19 27.4904 27.4904 27.4904 ZT20-23 21.24865 21.24865 21.24865