On the US government homepage, www.firstgov.gov, I searched for the terms 'deportation statistics'. This led me to the US Citizenship and Immigration Services. This website should be of great use to you, since they put yearbooks out with a number of different statistics. You may want to look around this website, and at this page,
US CIS Archives
is a listing of all recent yearbooks for immigration statistics.
The most recent year that seems most useful to use seems to be 2003, but this is because I could look at the excel files- this one in particular:
2003 CIS Yearbook
On this page, look at table 40- Aliens expelled: fiscal years 1892-2003. Now, the numbers for years 1961 to 2003 are given singly. From 1892 to 1960 the information is given by decade.
The title of this excel file seemed fairly straightforward. Other tables have funnier names, but there is an index to the terms:
CIS Definitions
Terms like 'deportable alien' vs a deported person will be figured out there.
Also, please search the Radical Reference site for the term 'deportation'. There is another answered question on our website that will lead you to pages of the Immigration and Customs Enforcement Agency, as well as the US Customs and Border Protection Site.