Explain the role of 'certainty' in project evaluation decisions.
$$
\begin{array}{lll}
\hline \hline \text { Year } & \text { Annual net cash flows (\$M) } & \text { Salvage value (\$M) } \\
\hline 0 & 23.00 \text { (Cost) } & \\
1 & 4.865 & 21.0 \\
2 & 3.956 & 18.7 \\
3 & 2.875 & 16.1 \\
4 & 2.115 & 14.3 \\
5 & 1.875 & 12.8 \\
\hline \hline
\end{array}
$$