A snowstorm started a midnight. For the first 4 hours, it snowed at an average of one-half inch per hour. The snow then started to fall at an average rate of one inch per hour for the next 6 hours. Then it stopped snowing for 3 hours. Then it started snowing agains at an average rate of one-half inch per hour for the next 4 hours until the storm was over. Determine the average rate of snowfall over the length of the storm. State the rate to the nearest hundredth of an inch per hour.