Please show work. I keep getting 7.9% and then 14% not sure if I am doing this right.

Six years ago, Bradford Community Hospital issued 20-year municipal bonds with a 7 percent annual coupon rate. The bonds were called today for a $70 call premium--that is, bondholders received $1,070 for each bond. What is the realized rate of return for those investors who bought the bonds for $1,000 when they were issued?