Cystic fibrosis is a genetic disease that is caused by a recessive allele (f). Homozygous dominant individuals (FF) do not have cystic fibrosis, but homozygous recessive individuals (ff) do have the disease. Heterozygotes (Ff) are carriers of the disease and generally do not have symptoms, although some may have mild symptoms. If 9% of the population is born with cystic fibrosis, what percentage of the population are carriers of the disease?