2009-07-01 to 2009-10-01 (13 threads) 2009-04-01 to 2009-07-01 (33 threads) 2009-01-01 to 2009-04-01 (22 threads) 2008-10-01 to 2009-01-01 (6 threads) 2008-07-01 to 2008-10-01 (9 threads) 2008-04-01 to 2008-07-01 (11 threads) 2008-01-01 to 2008-04-01 (1 thread)