Xavier left his house at time zero and drove to the store, which is 18 blocks away, at a speed of 9 blocks per minute. Then he stopped and went into the store for 2 minutes. From there, he drove in the same direction at a speed of 2 blocks per minute until he got to the bank, which is 6 blocks away from the store. He stopped at the bank for 3 minutes. Then he drove home at a speed of 4 blocks every minute. Make a graph of showing the number of blocks away from home that Xavier is xx minutes after he leaves his house, until he gets back home.