Long term trends. A annual number of individuals screened for malaria and % positive for P. falciparum from 1999–2011. B Annual numbers of individuals positive for P. falciparum (Pf) and P. vivax (Pv). C Median (IQR) age for those with P. falciparum from 1999–2011. D Annual number and % of individuals with P. falciparum from CHT 2002–2011 (data on area of residence were not collected before 2002).