According to published sources, we have about 1.5 million muslims in the US out of a total population of about 300 million, or about 0.5%. This is actually a smaller proportion than the 1.75% you stated for Oz. However, they are plenty loud and plenty obnoxious when they are in groups!
Interesting. I wonder if that 1.5 million is a true figure. I Googled:
Number of Muslims in the U.S.
This is a political hot-potato. Some non-Muslims have accused Muslims of exaggerated their numbers in order to obtain more political clout. Some Muslims have accused non-Muslims of releasing false, low numbers in order to "marginalize" Islam. 4 In religion, as in war, truth is often the first casualty.
Estimates of the number of Muslims in North America range from a little over one million adults to seven million adults and children. One cause of the disagreement appears to be related to the percentage of Muslim immigrants:
Who have abandoned Islam since they arrived in the US, or
Who still consider themselves to be Muslims, but who do not participate in mosque activities.
Here's another one:
It is very difficult to estimate the precise number of Muslims currently living in the United States. Muslims tend to put the number somewhat higher than non-Muslim scholars and demographers; the estimated figures range widely - from around two million in one study to as many as seven million. There are several reasons for the varying estimates. First, because the U.S. Constitution mandates a separation of church and state that is reflected in American law, U.S. Census Bureau survey forms do not ask recipients about their religion. Neither does the U.S. Immigration Service collect information on the religion of immigrants. Many mosques in the United States do not have formal membership policies, and they seldom keep accurate attendance figures. In the words of University of Chicago religion scholar Martin Marty, "Counting noses has come to depend on two sources. One source is poll-takers calling during the dinner hour to ask, `What is your religious preference?' The other source is religious leaders, on both the local and the national scene. People who respond to telephone interviewers may have all kinds of motives for declaring themselves as part of this or that group, or no group at all. And people who report on the size of their congregations, denominations, and cohorts also have a variety of motives." The end result is that there is no official count of Muslims in the United States nor is there a number that is commonly accepted by all who have studied the question.