Prepending zero on negative percentage numbers -10<n<-9

[nicholasruunu]

This is:

• a bug report
• a feature request
• not a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

What is the expected behavior?

-9.0%, -9.1%, -9.2%, -9.3%, -9.4%, -9.6%, -9.6%, -9.7%, -9.8%, -9.9%, -1.0%

What is the current behavior?

-9.0%, -09.1%, -09.2%, -09.3%, -09.4%, -09.6%, -09.6%, -09.7%, -09.8%, -09.9%, -1.0%

What are the steps to reproduce?

<?php

require __DIR__ . '/vendor/autoload.php';

use PhpOffice\PhpSpreadsheet\Style\NumberFormat\Formatter;

foreach (range(-0.090, -0.100, 0.001) as $value) {
    echo Formatter::toFormattedString($value, '0.0%') . PHP_EOL;
}

What features do you think are causing the issue

• Reader
• Writer
• Styles
• Data Validations
• Formula Calculations
• Charts
• AutoFilter
• Form Elements

Which versions of PhpSpreadsheet and PHP are affected?

Tried 1.29 and 2.0.0