let Y_{t} = current national income and

N_{t} = current population we are looking for

((Y_{t+1}/N_{t+1})-(Y_{t}/N_{t})l/(Y_{t}/N_{t})

We can we can multiply through get the percent change in per capita income as

(Y_{t+1}/Y_{t)}/(N_{t+1}/N_{t -1}

now Define n such that (1+n)=N_{t+1}/N_{t}

and y such that (1+y)= Y_{t+1}/Y_{t}

so, change in per capita income is (1+y)/(1+n)-1

In in this example that becomes

1.015/1.025 -1

this is close to minus 1%.

The population is growing 1% faster than income so income per person is shrinking by about 1% although not exactly.

If you have any questions in macroeconomics please feel free to reach out I know this stuff cold