Are there time-series of Bitcoins in circulation? For a study on Bitcoin, I would like to find (or construct) a timeseries of the total value of all Bitcoins in circulation (market capitalization). At least for the last two or so years. This could be quoted in e.g. US Dollar.

Is there such a time series? If not, is there a timeseries with the total amount of unlocked bitcoins, which could then be multiplied with an exchange rate?
Historical time-series of exchange rate:


https://docs.google.com/spreadsheet/ccc?key=0AmcTCtjBoRWUdHJuUE1mUkFxa3A0eHBDQkxZLVVFZmc


Source of the data is the "Raw Data" from BitcoinCharts.com.

The raw data of daily "market cap" is available in json


http://blockchain.info/charts/market-cap?timespan=all
http://blockchain.info/charts/market-cap?timespan=all&amp;format=json &lt;-- Thanks to Ben's comment below.