Solution:
Consider the exponential model

Where A is the population, and t is years after 2003. Then if A= 1315 million, the above equation becomes:

solving for the exponential e, we get:

that is:

now, applying natural logarithm to both sides of the equation, we obtain:

this is equivalent to:

solving for t, we get:

that is, 748.08 years after 2003, that is, in the year:2751.08
So that, the solution is:
The population of the country will be 1316 million in the year 2751.08 or 748.08 years after 2003.