The Comité Interprofessionnel du Vin de Champagne (CIVC) said the number of bottles sold fell 1.8% to 302 million in 2018, though total revenue edged up 0.3% to a record 4.9 billion euros (US$5.6 billion) as prices rose.

“The fall in volume is becoming a bit worrying, with the slowdown in France and Britain not compensated by higher sales outside the European Union,” CIVC co-president Jean-Marie Barillere told Reuters.

French and UK sales together account for about 60% of total sales by volume.

French sales fell 4.2% to 147 million bottles, with more bottles sold abroad than in France for the first time in 100 years, as a slow economy and the yellow vest anti-government protest movement weighed on sales.

Barillere said the protests had hit Paris tourist arrivals and French household confidence, hurting demand.

Total export sales edged up 0.6% to nearly 155 million bottles, but total export revenue rose 1.8% to 2.9 billion euros as the focus on the value of big houses, such as LVMH’s Moët & Chandon and Pernod Ricard’s Mumm, the world’s best-selling champagne, paid off.

In Britain, sales fell for the third year in a row, due in part to uncertainty sparked by the country’s planned departure from the European Union.

Volumes dropped 3.6% to 26.8 million bottles for total revenue of 406 million euros. Volumes had already fallen 11% in 2017 and 9% in 2016.

CIVC said champagne was feeling strong competition from Italian prosecco, which is three to four times cheaper.

Sales to the United States increased by 2.7% to 23.7 million bottles for revenue of 577 million euros.

Sales to Japan were up 5.5% to 13.6 million bottles, while sales to Hong Kong and China – each accounting for more than 2 million bottles – were up 12 and 10.1% respectively.

The biggest sales increase was seen in South Africa, where volume was up more than 38% to 1.1 million bottles.