percentConvert -- Converts percent value to decimal.
Synopsis
$err = $mod->percentConvert($data);
Description
This function converts a percentage
into a decimal.
Examples are:
"2%"
"6.4%"
"204 percent"
"2"
Returns
Returns a string representation of the given data (or -1 if an error
occurred). In case of error, the program will croak() with an appriopriate message.