Thank you all for your responses! Manish, I gave the correct answer to Maxgro because my real dataset actually has more than 3 values in the Market field, and the inline statement for Breakdown % also allows me to keep my values in a separate file, so his script was easier to adapt. But thank you so much for your fast response.
You can mark helpful the answer of the people (Manish, Saravana, Marco) with correct answer but not the one you prefere. The real help from the community is to have different ways to answer the same question.