I gave a questionary to 190 people to answer some questions. I want to check the correlation between the annual salary and how satisfy people are. So my two variables are annual salary and satisfaction. The data from annual salary are grouped into 6 categories: those without annual salary 0, 1-10,000 (10), 10,000-25,000 (25), 25,000-50,000 (50) , 50,000-75,000 (75), 75,000-100,000 (100) and above 100 (200). The satisfaction takes values form 0 to 10 (10 is very satisfied). My advisor suggested to do a regression but I found the $R^2$ = 0.01. I also tried to make a scatter plot but the data look strange.
Could you please suggest how to find the correlation between these two variables?
I attach an example of my excel spreadsheet with the data.