Figures for the number of service personnel stationed overseas can be found in table 1.1 of Tri-Service Publication (TSP) 10: UK Regular Forces stationed location. TSP 10 is published quarterly. The most recent publication shows figures at 1 October 2008 and can be found at:
http://www.dasa.mod.uk/applications/newWeb/www/index .php?page=48&pubType=0&thiscontent=1800&Publish Time=09:30:00 &date=20090223&disText=01%20Oct%202008 &from=listing&top Date =2009-02-23