Here are a few statistics I found. I am not sure if they are the same
ones you did..
In 1990, the Muslim population in US was approx 500,000. In 2000, the
Muslim population grew to approximately 1.1 million.
There are no official U.S. census statistics since Public Law 94-521
prohibits the U.S. gov't from asking a question on religious
affiliation on a mandatory basis; therefore, the Bureau of the Census
is not the source for information on religion.
According to the 2004-2005 Statistical Abstract of the United States,
the Self Described Religious affiliations of the US population states:
there were approximately 527,000 Muslims in the U.S. in 1990. In
2001, there were approximately 1,104,000 Muslims living in the U.S.
These are the sources in regard to the U.S.
Exerpt from: http://www.nationmaster.com/encyclopedia/Demographics-of-Islam
"Based on the percentages published in the 2005 CIA World Factbook
("World"), Islam is the second-largest religion in the world.
According to the World Network of Religious Futurists, the U.S. Center
for World Mission, and the controversial Samuel Huntington, Islam is
growing faster numerically than any of the other major world
religions. Ontario Consultants on Religious Tolerance estimate that it
is growing at about 2.9% annually, as opposed to 2.3% per year global
population growth. This is attributed either to the higher birth rates
in many Islamic countries (six out of the top-ten countries in the
world with the highest birth rates have a Muslim majority ) and/or
high rates of conversion to Islam.
Commonly cited estimates of the Muslim population today range between
900 million and 1.4 billion people (cf. Adherents.com); estimates of
Islam by country based on US State Department figures yield a total of
1.48 billion, while the Muslim delegation at the United Nations quoted
1.2 billion as the global muslim population in Sept 2005.
Only 18% of Muslims live in the Arab world; 20% are found in
Sub-Saharan Africa, about 30% in the Indian subcontinental region of
Pakistan, India and Bangladesh, and the world's largest single Muslim
community (within the bounds of one nation) is in Indonesia. There are
also significant Muslim populations in China, Europe, Central Asia,
Austria was the first European country to recognise Islam as an
official religion, while France has the highest Muslim population of
any nation in Europe, with up to 6 million Muslims (10% of the
population). Albania is said to have the highest proportion of
Muslims as part of its population in Europe (70%), although this
figure is only an estimate (see Islam in Albania). The number of
Muslims in North America is variously estimated as anywhere from 1.8
to 7 million."
On the link above, you will also see further links which will take you
to the statistics for the populations of Islam in the world.
Go to this link to get the information of the world by year by
Islam populations statistics of the World Sources:
For further analysis, you may want to consider UNESCO Statistical
Yearbook, Statistical Yearbook (United Nations), International
Historical Statistics, Statistical Abstract of the World. These books
can be found in your state library.
Hope this helps.