How long did it take to paint the sistine madonna?

The Sistine Madonna is an oil painting. The artist behind it is the Italian painter Raphael Sanzio. In 1512, he was assigned by the pope Julius II to create this masterpiece which was to be an altarpiece for the church of San Sisto in Piacenza. There is no accurate information about how long did it take the artist to paint it, but it is assumed it was finished in 1513-1514. The painting portrays Madonna holding the baby Christ, with Saint Sixtus and Saint Barbara looking at them from the bottom.

White flour this don't make sense