Which mathematical test should I use?

I have a dataset showing the yearly stock returns for two investment styles (growth and value investing) as well as a column showing the difference between the returns for each year. I have attached a picture below.

I want to do a test to see if the difference is significant for each individual year, such that the test fills out the area highlighted in blue.

Which test do I use? And if I use that test, what is the Excel command I need?