Disable text entry for Matrix Column

So I have a Matrix question with 2 columns of constant sum text boxes.

I have set default choices to be displayed in all 9 rows of the first column and I want to disable text entry in that column so that respondent is not able to change those numbers.

I have this code but I am unable to rewrite it to only disable the 9 rows of the first column

jQuery("input[type='text']").prop("disabled",true);