By nearly all measures, Bitcoin has seen impressive growth, especially over the last couple of months. But where is that growth coming from? An economic researcher at BTC Global has measured Bitcoin saturation by looking at downloads of the Bitcoin client from Sourceforge by country.

In a blog post, Colin Osterman notes that, although some people downloading from Sourceforge are simply updating their software, many are downloading for the first time. Sourceforge breaks the information down by day, by country, and even by operating system.

Osterman looked at the number of downloads per capita year-to-date, with Canada coming out on top, followed by Australia, the United Kingdom, the United States and Germany.

Osterman says countries at the bottom of the list should not be ignored, because they are the most interesting.

“Some of the most exciting growth is happening in regions where saturation is currently low,” he writes.

Although China is well down the list of year-to-date downloads per capita, that country has seen an explosion in downloads this month, with 42 percent of its year-to-date downloads occurring in May, Osterman said.

He added, “Brazil is another country to watch, with 29 percent, followed by Taiwan and South Korea, each with 23 percent.”

The data set was limited to larger countries, including only those with a population greater than 20 million and more than 500 downloads year-to-date. That eliminates the Nordic countries, but Osterman notes that -- collectively -- Finland, Sweden, Norway, Denmark and Iceland have the greatest Bitcoin saturation.

Looking at the latest data from Sourceforge, there have been nearly 240,000 Bitcoin software downloads since the beginning of May, with 32 percent of downloaders coming from China and 84 percent using Windows. Year-to-date, downloads total 1.3 million, with the top country of origin for downloaders being the United States, at 27 percent of downloads.

The US also tops the list of total downloads year-to-date -- around 350,000. That's nearly double that of China, second on the list, which is followed by the United Kingdom.