Answer
$\displaystyle \lim_{t\rightarrow\infty}I(t)=100.$
The index is expected to be about 100, from the middle of 2012 onwards.
Work Step by Step
$t$ is "approaching $+\infty$" means that $t$ is assuming positive values of greater and greater magnitude.
Observing the graph, we have:
As $t$ assumes positive values of greater and greater magnitude, the function value approaches the value $100$.
So, we write
$\displaystyle \lim_{t\rightarrow\infty}I(t)=100.$
The index is expected to be about $100$, from the middle of 2012 onwards.
