An epidemiological investigation was started for a small town with a population of 1000 in west Africa during the 2014 Ebola outbreak. For this population , 4 cases occurred for the entire year from January 2014 to January 2015. The diagram indicates thatPerson 1moved into town in February and was diagnosed with disease in June, accruing4 persons-months. Person 2was a resident in the town at the start of the observations and developed the disease in July ,but died in September ,accruing6 person- month.

Person 3, a resident of the town ,developed the disease in august , accruing7 person -months. Person 4,another resident of the town ,developed disease in October and died in December , accruing9 person -months .The other 996 residents all stayed in the village for the full 12 months . The time -to event data for the cases is graphed below.

1. What is the prevalence of the disease in the town on January 1,2015?
2. What is the incidence rate of disease in this population in 2014?
3. What is the cumulative incidence of the disease during 2014? Round to nearest 1000^th.