SharePoint 2010 PowerShell Create Item

Hey guys,

I've got a question. I've created different items in a SharePoint list with the PowerShell, but the problem is that this should be years and if I add, e.g. 2000 it is converted to 2,000. I don't know why it is doing so. What can I do to avoid this via PowerShell.

I use $newItem["Listname"]=2000

Best regard and thanks in advance

Matthias