A manual for writers of research papers, theses, and dissertations, 7th edition - Kate L. Turabian 2007

Commas within numbers
Numbers
Part III. Style 20 spelling

In most numbers of four or more digits, set off thousands, hundreds of thousands, millions, and so on with commas. In the sciences, commas are often omitted from four-digit numbers.

1,500

12,275,500

1,475,525,000

Do not use a comma within a four-digit year; do use one for years with five or more digits (see also 23.3).

2007

10,000 BC

Do not use a comma in four-digit page numbers, street addresses, telephone or fax numbers, zip codes, decimal fractions of less than one, or organization names.

page 1012

0.1911 centimeters

Committee of 1000