According to my MacOS I10n System Preference Pane, the US, the UK, and Ireland all use the same number punctuation (save currency symbols, obviously).

The French use the comma as the decimal delimiter and a space as a thousands delimiter.

Portugal: 1.234,56
Spain: 1.234,56
France: 1 234,56
Belgium: 1.234,56
Netherlands: 1.234,56
Germany: 1.234,56
Austria: 1.234,56
Italy: 1.234,56
Switzerland: 1'234.56
Denmark: 1.234,56
Norway: 1 234,56
Sweden: 1 234,56
Finland: 1 234,56
UK: 1,234.56
Ireland: 1,234.56

That's most of Western Europe.