Excel Conditional Formatting for cells that re equal to 0 formats also blank cells?

I have columns filled with this possible data

• 0
• 1
• na
• blank cells

I want to apply conditional formatting with this rules:

• if cell value = 0 , then the background is red
• if cell value = 1 , then the background is green

Unfortunately if I create the rules for value =0, it is also colouring the 'blank' cells red:

My rules look like this:

I have also put special rule just to switch all banks to white but it has no effect. I have tried to change the rule for the "0" in many ways like checking if the value is between 0 and 0, but still the rule always colours the blanks. How can I create rule which will leave the blanks white and colour only the "0" cells?

I went through couple examples from Stackoverflow which suppose to fix this issue, but I dont know how to apply formulas in generic way for whole columns - I am not working with Excel on daily basis so I dont know how to create advanced formulas.