Suppose a firm has had the historical sales figure shown as follows. What would be the forecast for the next year's sales using the average approach?

\begin{tabular}{|lcccccc|} \hline Year & 2017 & 2018 & 2019 & 202 & 2021 \\ \hline Sales & $1,000,000 & $2,000,000 & $1,700,000 & $1,800,000 & $2,200,00 \\ \hline \end{tabular}