The consumption rate of Japanese sake is falling, and even famous sake breweries are in danger of going bankrupt.
Sake is less popular nowadays, and even famous sake breweries are in danger of going out of business.
消費量 = the amount of consumption
消費量 = consumption rate
「rate」と「amount」がちょっと違いますが、「the amount of consumption of Japanese sake」も「the consumption amount of Japanese sake」でも、ちょっと変に聞こえます。この状態で、「consumption rate」が一番言いそうな表現だと思います。
アメリカ合衆国 
