<prompt> Translate the following text to EnglishKwa mfano, ikiwa kuenea kwa ugonjwa hupungua kwa asilimia 25 na kupungua kwa PM, basi kiwango cha msingi cha maambukizi hupungua kwa asilimia 25 na kupungua sawa kwa PM.  <response>: For example, if the prevalence declines by 25 percent with a drop in PM, then baseline incidence drops by 25 percent with the same drop in PM. 