Based on the information from two surveys how would I Calculate the prevalence of people with histoplasmosis antibodies at the second survey and compare the prevalence with the 1-year incidence. (Calculate incidence per 1,000 persons per year) Please show me and explain the calculation for my understanding / knowledge

Two surveys were conducted (12 months apart) within a single sample of 5,000 people from the same community. From the first survey, 25 of the 5,000 had antibodies to histoplasmosis. Twelve months later, 35 had antibodies, including the original 25.