The proper place to put a percent sign in a range is as follows:
40-60% The percent sign is not used after both ranges (40 and 60)
when ranges are used. However, when a percentage range is not being
described, such as 40 percent, it is acceptable to place the
percent sign immediately following the digits (60 percent; 60%), or
a space may be used between the digits and the sign (60 %).