How to add text data to visualisations

Hello,

I need to make a visualisation where I have  2 Y axis (one for a number data, for instance 'sales' for instance $ 10,000, 20,000, 30,000 for 2016, 2017 and 2018 and other for text data for instance 'credit risk' which could be -A, A and A+ 2016, 2017, 2018 in this example the company improved their credit rating every year). The X value would be years 2015, 2016, 2017. The idea is showing that sales are related to the credit rating of the stores. Thus -A is lower than A and A is lower than A+.

I know I can use visualisations with 2 Y axis number values but I am having trouble adding the text value. In my example above, the line of credit risk should go up.

Any ideas?

Thanks in advance,

Luis