condition mean min max ZT0-3 11.558211 11.558211 11.558211 ZT4-7 9.6546935 9.6546935 9.6546935 ZT8-11 10.520044 10.520044 10.520044 ZT12-15 10.430557 10.430557 10.430557 ZT16-19 10.170948500000002 10.170948500000002 10.170948500000002 ZT20-23 11.012941999999999 11.012941999999999 11.012941999999999