In a factory that makes bolts, 20% of the bolts being made by a certain machine are defective. The factory owner wants to determine the probability that two bolts in a row will be defective. He decides to use random numbers as a simulation tool. The following list shows 100 two-digit numbers that were randomly generated to represent two bolts in a row. If he uses the digits 0 and 1 to represent defective bolts, how many times were two bolts in a row defective?

0
33
3
18