Coal production in Allied European countries 1900-1945, by country
Of the Allied European countries in the early 20th century, the United Kingdom had, by far, the largest annual coal output in each year. In most years, the UK's annual coal output ranged between 200,000 and 300,000 tons; this was more than all of the other given countries combined until the 1930s. As the Soviet Union industrialized and its economy grew in the years leading up to the Second World War, its coal output increased significantly, growing ten times larger between the mid-1920s and 1940. It has also been estimated that, when compared to the early-1930s, Poland's output more than doubled after it was annexed by Germany.