I looked around a bit, and there are a few things challenging this measurement. Buddhism and Hinduism explicitly conflate miracles with supernatural human powers, and seem to take a dim view of both (they're also not theistic in the relevant sense anyway). Islam reports many miracles (starting with the Holy Quran itself, of course), but since Al-Ghazali seems to reject material causality entirely in favor of everything being miraculous- the challenge here will be reporting events that a Christian would also interpret as miraculous or supernatural, which the religion tends to see as superstition. Judaism is probably insufficiently distinct from Christianity for your purposes. Wiccans certainly report many spirit communications and magical experiences, more often than most Christians- the invocation of these events is core to the faith, although again you might not consider these miraculous as such due to the lack of monotheism (an equivalent might be transubstantiation during the Catholic communion ceremony). Same with many new age spiritualists.

In other words, most world religions don't even really have false claims of contemporary miracles in the theistic sense you mean, for the same reason that Christians rarely report remembering their past lives. Islam and Wicca come closest, but these are both religions that were influenced by Christianity at the time of their founding. So even the 'Christianity is false' universe would predict a preponderance of miracle reports to exist within Christianity.