From: Xavier Noria <fxn@...>
Date: 2012-12-26T18:58:24+09:00
Subject: Re: Accumulate total count for each month

If that is all there is to it, a simple split would work

nevents = Hash.new(0)

ARGF.each_line do |line|
  month, year = line.chomp.split.values_at(1, -1)
  nevents["#{year} #{month}"] += 1
end