At a time when demand for ready$-$to$-$eat cereal was stagnant, a spokesperson for the cereal maker Kellogg's was quoted as saying, $"...$ for the past several years, our individual company growth has come out of the other fellow's hide." Kellogg's has been producing cereal since $1906$ and continues to implement strategies that make it a leader in the cereal industry. Suppose that when Kellogg's and its largest rival advertise, each company earns $$0$ billion in profits. When neither company advertises, each company earns profits of $$12$ billion.

If one company advertises and the other does not, the company that advertises earns $$52$ billion and the company that does not advertise loses $$4$ billion. For what range of interest rates could these firms use trigger strategies to support the collusive level of advertising?

Instruction: Enter your response as a percentage rounded to the nearest whole number.

$i$ :