Using Google Ngram, I noticed that pressocché ovunque appears from 1950, even though Lo Zingarelli 2013 reports that pressoché and pressocché are from XIII century.
Would a question asking how that is possible be acceptable?
It is perfectly acceptable to me that questions asking to interpret and discuss results by Google Ngram viewer appear on the site. The tool is very interesting, but it has to be remembered that, especially for Italian, we cannot take it as the ultimate truth, because all depends on how many and which books (how they are assorted among genres) are used for the frequency data.
This said, I don't actually understand your doubt, because in one case you search for a two-gram (pressocché ovunque) and in the other for a one-gram.