$7.$ The average annual exchange rate in Canada for the US dollar from $2008-2018$ is shown in the following table.

$\backslash$begin$\{$tabular$\}\{|$l$|$l$|\}$

$\backslash$hline Year & Exchange rate $\backslash \backslash$

$\backslash$hline $2008$ & $0\mathrm{.}94\backslash \backslash$

$\backslash$hline $2009$ & $0\mathrm{.}88\backslash \backslash$

$\backslash$hline $2010$ & $0\mathrm{.}97\backslash \backslash$

$\backslash$hline $2011$ & $1\mathrm{.}01\backslash \backslash$

$\backslash$hline $2012$ & $1\mathrm{.}00\backslash \backslash$

$\backslash$hline $2013$ & $0\mathrm{.}97\backslash \backslash$

$\backslash$hline $2014$ & $0\mathrm{.}91\backslash \backslash$

$\backslash$hline $2015$ & $0\mathrm{.}78\backslash \backslash$

$\backslash$hline $2016$ & $0\mathrm{.}77\backslash \backslash$

$\backslash$hline $2017$ & $0\mathrm{.}77\backslash \backslash$

$\backslash$hline $2018$ & $0\mathrm{.}77\backslash \backslash$

$\backslash$hline

$\backslash$end$\{$tabular$\}$