Elena has found a 4 year investment that pays 10% per annum, compounded annually, which allows him to add or withdraw cash at any year end without penalty. She puts $10,000 in today, withdraws $2,000 at the end of Y1 to pay for a vacation, adds $1,000 at the end of Y2, and withdraws $4,000 at the end of year 3. Create a time line that shows all cash flows for this investment.