Luxury Home Auctions Hit Full Stride

From a news release:

"A robust market for luxury properties does not guarantee overnight success for sellers of million dollar homes however. The number of homes priced at over 1 million or more in the United States is approaching 500,000. With the highest concentration of luxury real estate found in Massachusetts, Florida, U. S. Virgin Islands, and California."

Is that true? The Virgin Islands are so small, physically - does the "concentration" in the above mean percentage of or actual number of?