(Portland, OR)  --  A new report by Zillow shows the cost to rent an apartment is skyrocketing in Portland.  The real-estate website reports rents have risen over the past year, nearly two times faster than home values.  Zillow says the average home price in Portland rose four-point-seven percent during the past 12 months, while rent increased an average of eight-point-six percent.  Rent averages more than 16-hundred dollars a month in Portland, and the average home price is nearly 283-thousand dollars.