Im having some trouble solving this question..

I have 2 populations in which I have calculated the risck per patient-year for an specific event, in 2018 and 2019.

Now I have:

Event per patient-year:

Population 1

- 0.48 in 2018

- 0.32 in 2019

Population 2

- 0.61 in 2018

- 0.53 in 2019

What im trying to find is a way of proving that population 1 has a significant lower risk of events per patient-year than pop 2 (in each year and both years)

Is there a way of converting this into a p value?

Already tried t-test and Wilcoxon with no success, since I do not have a grouping variable…

Thanks in advance and sorry for some grammar errors and other simple stat mistakes.