Obtaining P values for 2 variables

#1
Hello,
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.
 
#2
Do you have the sample size for the each of the four groups?

Can you think of 0.48 as a proportion? A proportion of events.

Then you can run logistic regression with time and group as explanatory variables.