let Yt = current national income and
Nt = current population we are looking for
((Yt+1/Nt+1)-(Yt/Nt)l/(Yt/Nt)
We can we can multiply through get the percent change in per capita income as
(Yt+1/Yt)/(Nt+1/Nt -1
now Define n such that (1+n)=Nt+1/Nt
and y such that (1+y)= Yt+1/Yt
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