Negative percentages in a table of data I am writing a paper and I have a table outlining the percentage change of results in different conditions.  For example:

Condition A: 5%
Condition B: -7%

Essentially, I want to show that Condition A saw an increase with my method and Condition B saw a decrease.  However, my adviser recommended against negative percentages, saying a percentage should always be positive.  What is a proper way to format this?
I don't necessarily know that I agree with your advisor's perspective, but the way you could do this is having "baseline" be 100%, and the changes between method A and method B being deviations from 100%.

So for example, rather than 5% and -7% you'd have 105% and 93%. This, to me, seems entirely stylistic in many cases, however may be consistent with things in your field. For example, relative risks in epidemiology implicitly use a scale somewhat like this.