A politician campaigns in a very small town of $300$ resients. The number of people their campaigning team is able to reach, N$($t$),$ follows the logistic model N$($t$)=(300)/(1+700$e$^(-0\mathrm{.}5$t$))$ where t

is time $($in hours$)$ since the team arrived in the morning. At what time has the campaign reached the point of diminishing returns? $($Round your answer to the nearest hour$).$