public void SetUp()
        {
            isPoor[1994] = true;
            isPoor[1995] = true;
            isPoor[1996] = false;

            people = new List<Person>();

            foreach (string country in countries)
            {
                Person p = new Person(country, personId);
                foreach (int year in years)
                {
                    p.AddObservation(year, isPoor[year], isPoor[year] ? 0.3 : 0);
                }
                people.Add(p);
            }

            calculator = new PovertyPersistenceRatioCalculator(people);
        }