After more than a quarter of a century of rising diabetes rates, the number of new cases seems to be on a downward trend.

From 1980 to 2009, the annual number of new diabetes cases more than tripled in the US, going from 493,000 to 1.7 million diagnoses a year in people aged 18 to 79. But since 2009, case numbers appear to have slumped, though the decline had not registered as statistically significant. Now, using newly released data from 2014, the Centers for Disease Control and Prevention announced that case numbers are definitely on their first sustained decline. In 2014, the number of diagnosed cases was down to 1.4 million.

“It seems pretty clear that incidence rates have now actually started to drop,” said Edward Gregg, one of the CDC’s top diabetes researchers told the New York Times. “Initially it was a little surprising because I had become so used to seeing increases everywhere we looked.”

Experts are unsure of what’s driving the decline, however. It may be due to the fact that the disease simply peaked in the American population. Or, the decline could be evidence of effective health campaigns. Other studies and surveys seem to back the latter; they have found that Americans are eating healthier, including guzzling less soda and cutting calories. Exercise levels are also starting to look up and obesity rates appear to have hit a plateau, according to the Times.

Still, it’s not time to celebrate yet—1.4 million new cases of diabetes is still a very high rate of diabetes cases.