A census from the year 1490 survives and it lists 51 taxpayers for Ulmet (but not the other inhabitants). In 1609, 259 inhabitants were counted. Exact population figures for the time from 1638 to the early 19th century are unavailable. Only in 1802 was another population count and this time there were 362 inhabitants. The rise became continuous, but by the mid 19th century, the effects of emigration to the United States and Southeastern Europe had taken their toll on the population figures, which were now shrinking. Between the end of the Franco-Prussian War and the turn of the 20th century, population growth stagnated as a result of inhabitants moving away to Germany's industrial regions; it was likewise after the First World War. At the last census before the Second World War, Ulmet had 754 inhabitants, and once again, there was an upward trend. Beginning in 1978, there was a temporary drop in population, but this was a bureaucratic illusion, for commuters were counted at their workplaces, not at their homes. This was, however, followed by slight growth in population. With regard to religious affiliation, Protestants were the overwhelming majority in Ulmet. Over time, though, the Catholics managed to increase their percentage of the population slightly. For a time, almost 10% of the inhabitants were Jewish. The Jews’ share of the population, however, had already begun to shrink steadily by the 19th century, mostly owing to migration to the industrial regions.