In the first week of July, a record of 1100 people went to the local swimming pool. In the second week, 105 fewer people went to the pool than in the first week. In the 3rd week, 130 more people went to the pool than in the second week. In the fourth week, 135 fewer people went to the pool than in the third week. What is the percent decrease in the number of people who went to the pool over these four weeks