In 1995 an anonymous private collector purchased a painting by Picasso entitled Angel Fernandez de Soto for $29,152,000. The picture depicts Picasso's friend de Soto seated in a Barcelona cafe drinking absinthe. The painting was done in 1903 and was valued then at $600. If the painting was owned by the same family until its sale in 1995, what rate of return did they receive on the $600 investment?