code: @Nonnull
    public static String getFormattedPercent (final double dValue, @Nonnull final Locale aDisplayLocale)
    {
      ValueEnforcer.notNull (aDisplayLocale, "DisplayLocale");
  
      return NumberFormat.getPercentInstance (aDisplayLocale).format (dValue);
    }
docs: Format the given value as percentage. The "%" sign is automatically
  appended according to the requested locale. The number of fractional digits
  depend on the locale.
  
  @param dValue
  The value to be used. E.g. "0.125" will result in something like
  "12.5%"
  @param aDisplayLocale
  The locale to use.
  @return The non-<code>null</code> formatted string.