US Robotics is evaluating a new product line. The CFO asks for an estimate of number of years to recover the initial investment, ignoring the time value of money. You realize that this is the payback period. The estimated cash flows from the new product line appear below.

$($Answer in years, round to $2$ places$)$

Year $0$ cash flow $=-88,000$

Year $1$ cash flow $=-42,000$

Year $2$ cash flow $=28,000$

Year $3$ cash flow $=30,000$

Year $4$ cash flow $=40,000$

Year $5$ cash flow $=44,000$

Year $6$ cash flow $=37,000$

Year $7$ cash flow $=44,000$