Some facts and stats, compiled at PoeticEconomics:

# of open access journals : over 6,000. Growth rate: 4 per day.

# of freely available journals: over 28,000. Growth rate: 10 per day.

# of open access repositories: close to 2,000 . Growth rate: 1 per day.

# of documents freely available: 25 million. Growth rate: 6,000 per day.

# of open access mandate policies: 271. Growth rate: 1 per week or 5 per month.

% of world’s scholarly literature that is freely available: 20%

The sources are here.

Categories: copyright, open access dw