Ten years ago your client purchased a set of silver coins for $21,000. Today, the current price is $37,000 more than her cost basis. Over the years she paid $600 per year for storage and insurance. She expects to incur $1000 in Assay expenses at the time of the sale. Two weeks after making her return calculations, she finally completes the sale of her coins at a price of $42,000. What is her ex post HPR?