The Pell Grant program of the federal government provides financial aid to needy college students. A supplemental grant of $690 per recipient in the 2012–2013 school year (toward the maximum total of $5550) will increase annually until 2017 to account for inflation. Beginning in 2018, grants will no longer increase with inflation. If the maximum total Pell Grant award increases to $5645 in the 2013–2014 school year, what inflation rate per year was used in the calculation?