Percentages and percentage points
Use the percentage symbol (%) with no space between it and the number. This symbol can be used as it is read out by screen readers.
The goalie saved 91% of the penalties.
Use the same number of decimal places for a sequence of percentages.
There were increases of 17.20%, 6.18% and 5.67%.
A percentage point is the difference between percentages. A value of 10% falling by 1 percentage point becomes 9% (10% has 10 percentage points). A fall of 1% would result in a value of 9.9%.
When writing about percentage points, always use "percentage" and never "%age". The word "points" should always be plural, except for when referring to 1 percentage point.
The sector grew by 0.7 percentage points, while the industry grew by 2.6 percentage points.
The sector grew by 1.0 percentage point.