A group of hardworking young investigators is able to obtain funding for a large study in King George County on Lyme disease. They recruit 5000 adults to their study and decide to follow them for 1 year (when the funding runs out!). In initial blood work they find 85 people who test positive for exposure to the causative bacteria or report a past confirmed positive test. Unfortunately, these people can acquire Lyme disease again but because it will be difficult to know if it is a new infection from blood work the researchers decide they are only interested in first time cases of Lyme disease. Over the next year they test the remaining eligible subjects bimonthly. The study begins in June and the next tests are done August, October, December, February, April, and June (end of year 1). For the purpose of this exercise we can see into the future and below is a summary of their results: Month August October December February April June Year 1 2+'s 1+ 0+ 0+ 0+ 1+ OLTFU 15 LTFU 5 LTFU OLTFU OLTFU 10 LTFU LTFU means lost to follow up (therefore they were only followed up to the previous checkup) + is a positive blood test. Once they test positive they are no longer included in the above table. For calculations it is assumed they became positive halfway between the checkups on average. (hint: these footnotes on tables can be very important so read them!!) 15. They want to calculate the incidence rates year 1. Why don't they count the 85 who tested positive at the start? (1 pt) 16. What was the total person time observed from participants who stayed in the study but never tested positive? (1 pt) 17. How much at-risk person time can be counted as from the cases? (1pt)