condition mean min max ZT0-3 20.457933333333333 18.009700000000002 23.2053 ZT4-7 23.458599999999997 23.458599999999997 23.458599999999997 ZT8-11 12.38845 12.38845 12.38845 ZT12-15 15.956875 15.0648 16.84895 ZT16-19 13.859449999999999 13.859449999999999 13.859449999999999 ZT20-23 16.271 16.271 16.271