The populations for the respective years are:
- \( P(2010) = 310.0 \) million
- \( P(2011) = 313.007 \) million
- \( P(2012) \approx 316.0432 \) million
- \( P(2013) \approx 319.1088 \) million
Thus, the final answers are:
\[
\boxed{P(2010) = 310.0, P(2011) = 313.007, P(2012) \approx 316.0432, P(2013) \approx 319.1088}
\]