Given all the bots, both in terms of vandals and in repulsing them, I am not sure the following question even makes sense: but how can we characterize the ratio of productive to unproductive contribution/edits on the English Wikipedia? Has this changed over time? I do have figures from the literature on percentages (and their deltas) for administrator activity, policy edits, time to revert vandalism, etc. The only data point I can find is a single one: the "Bush article had 28,000 revisions, one-third were reverts and, conceivably, another third vandalism" (Spinellis, Louridas 2008).