EDIT: Holy cow, at least four downvotes so far. I hope the downvotes are for nitpicking and not out of disagreement. As cakemuncher seems to disagree (which doesn't mean they downvoted) this seems like a great learning opportunity about decimal separators and non-native speakers:
The parent is most likely German (the example code uses German so that usually means Germany, Austria or Switzerland) which uses the comma as decimal separator and period as thousands separator. I'm German too, so I'm sensitized to this mistake.
Here's the Wikipedia article for reference: https://en.wikipedia.org/wiki/Decimal_mark
The US, the UK, New Zealand, Australia and English-speaking Canada all use the dot as decimal mark. South Africa is the only major English speaking country using a comma instead, but they use a space as thousands separator rather than a period.
The parent clearly intended "10.000%" to be read as "ten thousand percent" so that leaves the following list of countries which according to Wikipedia use a comma as thousands separator:
Argentina, Austria, Bosnia and Herzegovina, Brazil, Chile, Croatia, Denmark, Germany, Greece, Indonesia, Italy, Netherlands (currency), Portugal, Romania, Russia, Slovenia, Spain, Sweden (not recommended), Turkey
Exactly zero of these countries are predominantly English speaking. So in other words, in English 10.000% means ten percent (with a precision of three digits after the decimal point), not ten thousand percent.