Blackrock Capital is an investment firm that focuses on opportunities in South America. Blackrock had purchased Brazilian reals (BRL) a year ago when a BRL was worth $0.403 and then invested in a one-year Brazilian money market security that yielded a return of 15.0 percent (in BRL). At the end of the year, when Blackrock converted the investment from BRL to dollars, the BRL had appreciated in value to $0.418. Find the effective yield earned by Blackrock Capital.