Siamese cat phenotype frequency is 1 percent of stray cats

Defining the laboratory animal: IV Symposium, International Committee on ...(1971) says this about the Siamese cat. I quote verbatim and claim fair use as it is educational and I am referring to a small part of the text while promoting the work. (link to original page)

"Siamese on the other hand have been bred extensively. For instance, the gene frequency of the cat population at large in Paris (France) is 10 percent. That means phenotype frequency is 1 percent of that seen in stray cats. In Bangkok, the gene frequency is only 29 percent, and that is where they come from originally."

Some definitions:

gene frequency -- the frequency or proportion of genotypes in a population. "Genotype" means "the genetic makeup of a cell, an organism, or an individual".

phenotype frequency -- "an organism's observable characteristics or traits".