In recent decades, the literacy rate of Rajasthan has increased significantly. In 1991, the states literacy rate was only 38.55% (54.99% male and 20.44% female). In 2001, the literacy rate increased to 60.41% (75.70% male and 43.85% female). This was the highest leap in the percentage of literacy recorded in India (the rise in female literacy being 23%). At the Census 2011, Rajasthan had a literacy rate of 67.06% (80.51% male and 52.66% female). Although Rajasthans literacy rate is below the national average of 74.04% and although its female literacy rate is the lowest in the country, the state has been praised for its efforts and achievements in raising literacy rates.
Question: By how many percentage points did the overall literacy rate increase between 1991 to 2001?
Answer: 21.86