500 college students were enrolled in a study on January 1, 2020 and monitored for 1 year for infection with influenza. 300 of those college students received an effective influenza vaccine at baseline and were not at risk for influenza. 40 tested positive for influenza at baseline, 43 people tested positive for influenza on March 31 and 15 people tested positive for influenza on October 31. 25 people were lost to follow-up on February 29 and 30 people were lost to follow-up on November 30. No one lost to follow-up was infected with influenza prior to being lost.

1. What was the incidence rate of influenza infection within the study population? Show your work and express answer per 100 person-months and round final answer to 1 decimal place.