As a starter, the Allied Relief Expedition that left Tientsin 4th August 1900 consisted of:
10,000 Japanese
4,000 Russian
3,000 English (I take this to be British but this is how it was described in the report of Gen. Sir Alfred Gaselee - British Commander)
2,000 American
800 French
200 German
200 Italian
September 1900 saw a large influx of Allied troops, approx. 20,000 each for British & German and 5,000 American.
The official report of April 1901 gives:
Austria 300
England 18,181
France 15,670
Germany 21,295
Italy 2,155
Japan 6,408
Russia 2,900
USA 1,750
A total of 68,659
Svennn