1. The percentage, \(P\), of the population of a small country who have access to the internet, is modelled by the equation

$$P = a b ^ { t }$$ where \(a\) and \(b\) are constants and \(t\) is the number of years after the start of 2005
Using the data for the years between the start of 2005 and the start of 2010, a graph is plotted of \(\log _ { 10 } P\) against \(t\). The points are found to lie approximately on a straight line with gradient 0.09 and intercept 0.68 on the \(\log _ { 10 } P\) axis.

1. Find, according to the model, the value of \(a\) and the value of \(b\), giving your answers to 2 decimal places.
2. In the context of the model, give a practical interpretation of the constant \(a\).
3. Use the model to estimate the percentage of the population who had access to the internet at the start of 2015