Adding a '%' after each value automatically

I'm not a huge fan of formatting cells as a percent in Excel because it automatically multiplies the value by 100.

I want to write my own VBA function that looks for a change in value in a particular cell and adds a '%' to the end of it.

How can I write some 开发者_开发知识库code to look for changes automatically?

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Change the format string to 0\%.
The \ escapes the percent character and prevents Excel from multiplying it by 100.