condition mean min max ZT0-3 9.707831 9.707831 9.707831 ZT4-7 10.8239005 10.8239005 10.8239005 ZT8-11 10.4015065 10.4015065 10.4015065 ZT12-15 10.880793 10.880793 10.880793 ZT16-19 10.141265 10.141265 10.141265 ZT20-23 9.619746 9.619746 9.619746