Dave Clegern, a spokesperson for the California Air Resources Board, which oversees the electric car mandates, said in an email that while sales of zero-emission vehicles in California are “less dramatic than in years past,” the flat sales occurred in the context of an overall plateauing of car sales last year.

After three straight years of strong growth, sales have stabilized in California, raising questions about whether the state will fail to meet its groundbreaking mandate banning sales of gas-powered vehicles.

Douglas McIntyre, editor-in-chief at Climate Crisis 24/7, reports that EV sales in California—America’s largest EV market—grew by just 1% last year. With the state leading the push for EV adoption, this stagnation raises concerns for the rest of the country.