condition mean min max ZT0-3 0.2774975 0.2774975 0.2774975 ZT4-7 0.33833650000000004 0.33833650000000004 0.33833650000000004 ZT8-11 0.506066 0.506066 0.506066 ZT12-15 0.38563100000000006 0.38563100000000006 0.38563100000000006 ZT16-19 0.12613059999999998 0.12613059999999998 0.12613059999999998 ZT20-23 0.31145900000000004 0.31145900000000004 0.31145900000000004