Yesterday's announced attendance of 17,029 was our seventh-lowest of the season:
17,029 Tuesday 23rd August 2011 vs Diamondbacks [the earthquake]
16,914 Wednesday 13th April 2011 vs Phillies
15,342 Monday 2nd May 2011 vs Giants
15,142 Thursday 28th April 2011 vs Mets
14,603 Tuesday 26th April 2011 vs Mets
13,568 Wednesday 27th April 2011 vs Mets
13,413 Tuesday 12th April 2011 vs Phillies
...lowest ever at Nats Park against the Diamondbacks:
27,330 Thursday 10th July 2008 vs Diamondbacks
26,820 Tuesday 8th July 2008 vs Diamondbacks
25,862 Wednesday 9th July 2008 vs Diamondbacks
24,551 Saturday 8th August 2009 vs Diamondbacks
22,674 Friday 7th August 2009 vs Diamondbacks
22,400 Saturday 14th August 2010 vs Diamondbacks
21,695 Sunday 15th August 2010 vs Diamondbacks
19,938 Sunday 9th August 2009 vs Diamondbacks
19,549 Friday 13th August 2010 vs Diamondbacks
19,377 Monday 22nd August 2011 vs Diamondbacks
17,029 Tuesday 23rd August 2011 vs Diamondbacks
...also fourth-lowest attendance at an August Nats Park match ever:
17,029 Tuesday 23rd August 2011 vs Diamondbacks
16,496 Thursday 12th August 2010 vs Marlins
16,187 Wednesday 19th August 2009 vs Rockies
15,061 Wednesday 11th August 2010 vs Marlins
[all of the above excerpted from my complete listing of Nats Park announced attendances]