Hello, I need assistance with the following question pertaining to the graph below:

22. What was the incidence density/rate during the study in person-months of observation?

Ilse the information in the passage below to answer the following questions (SHOW YOUR WORK) (numerator, denominator, equation, and interpretation of answer). An epidemiological investigation that began on January 1, 2009, identified a population of 1,000 individuals, among whom 4 were found to have the disease. During the year- long study, 6 additional new cases were found. Among the incident cases, 3 cases died during the year-long study. Study duration was January 1 December 21, 2009. For each of the 10 cases, the table below indicates the time of case diagnosis, periods of observation during the study, and vital status at the time of the termination of observation. An arrow (