Thirty sixteen-year-olds took the driving test to obtain their driver's license. The following chart shows the number of times each one had to take the test before passing. 1 3 1 1 2 1 2 3 2 1 2 1 1 3 2 1 1 1 1 2 1 1 2 1 3 2 1 1 1 2 Based on the above data, what is the mode?