Passage

Directions : Study the following information and answer the question that follows. Five persons − Harry, Rose, Emily, Sean and William − are playing a game in which they have to enter some number (input), and the output generated is distinct each time. The output would be bigger than the number entered. Every person gets one chance and they enter a distinct number. Also, the difference between the input number and the output number is also different for every person. The input numbers, the output numbers and the difference between the input and output numbers are all positive integral multiples of 5. The following information is known about the input, the output and the difference between the input and output numbers for each person: (1) Rose's input number is 20 and the difference between the input and output numbers of Rose is 5 more than the difference between the input and output numbers of Emily. (2) Harry's output number is 50 and his input number is 5 more than the input number of Sean. (3) The output number of William is at least 45, while the input number for him is at least 25. (4) The input number of any of the five persons is not greater than 40, while the output number of any of the five persons is not greater than 55. (5) The difference between the input and output numbers of Rose is 10 more than the difference between the input and output numbers of Sean. (6) Emily's output number is 35 and the difference between the input and output numbers of Emily is 20 less than the difference between the input and output numbers of Harry.

The average input number is how much percent less than average output numbers for all the friends combined?