Tony Cliff defends the Bolshevik policy, stating that "the number of industrial workers in Russia, always a minority, fell from 3 million in 1917 to 1,240,000, a decline of 58.7%, in 1921-22. So was there a decline in the agricultural proletariat, from 2,100,000 in 1917, to 34,000 only two years later . But the number of peasant households  had risen with the parcelization of land from 16.5 million in early 1918 to over 25 million households by 1920, an increase of some 50%." According to this view, the majority of the sailors in the Baltic Fleet stationed at Kronstadt were recent recruits of peasant origin. Stepan Petrichenko was himself a Ukrainian peasant. He later acknowledged that many of his fellow mutineers were peasants from the south, who were in sympathy with the peasant opposition movement against the Bolsheviks. In the words of Petrichenko: "When we returned home our parents asked us why we fought for the oppressors. That set us thinking."
Question: How many years did it take for the number of peasant households to increase by 50%?
Answer: 2