For this case, my personal preference would be to use Format
function. Like this:
PercentChangeText.Caption := Format('%.2f%%', [PercentageChange]);
It's easier to inspect what the result will be and supports formatting multiple values.
On your coding style, I see there were many redundant parentheses. The outermost ones were not needed. Also the innermost ones (those that surround PercentageChange
). When not really needed, parentheses tend to block the flow of thought of the reader. When readers' eyes hit a parenthesis (especially the closing one), their mind will start finding out which group the parenthesis defined.
Nothing technically bad about it, though.