Construct a table and a graph showing the relationship between interest rates, time, and future value by showing how $8000 would grow each successive year over a 20-year period at different interest rates. 

Use $8000 for your present value and calculate the future value of this $8000 each year over the 20-year period at 0%, 3%, 6%, 9%, 12%, 15%, 18%, and 21% compounded semi-annually. 

Future Value should be the y-axis for your graph and years (or time) should be your x-axis and you should end up with a line for each interest rate on your graph.