Schulte im Walde & Melinger (2008) found that the correlation between co-occurrence derived association scores and human association norms were weakly dependent upon the window size used to calculate the former, but that certain associations tended to be represented at certain window sizes, by virtue of the fact that the best overall correlation was found by combining evidence from all window sizes.
put, the figures show the percentage of times a given association score or lower was measured between word types in a corpus which is known to be devoid of any actual syntagmatic association.