http://www.nhpco.org/ has been crawled 635 times going all the way back to May 10, 2000.

A crawl can be a duplicate of the last one. It happens about 25% of the time across 420,000,000 websites. FAQ

Jan
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January 6, 2011

2 snapshots

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January 13, 2011

1 snapshot

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January 14, 2011

1 snapshot

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January 19, 2011

1 snapshot

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January 20, 2011

1 snapshot

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January 26, 2011

1 snapshot

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January 27, 2011

1 snapshot

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Feb
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February 3, 2011

2 snapshots

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February 4, 2011

1 snapshot

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February 10, 2011

2 snapshots

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February 17, 2011

1 snapshot

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February 24, 2011

1 snapshot

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February 25, 2011

1 snapshot

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Mar
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March 2, 2011

1 snapshot

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March 9, 2011

1 snapshot

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March 17, 2011

1 snapshot

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March 25, 2011

1 snapshot

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March 30, 2011

1 snapshot

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Apr
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April 6, 2011

1 snapshot

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April 8, 2011

1 snapshot

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April 13, 2011

1 snapshot

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April 20, 2011

1 snapshot

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April 29, 2011

1 snapshot

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April 30, 2011

1 snapshot

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May

May 1, 2011

1 snapshot

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May 6, 2011

1 snapshot

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May 13, 2011

1 snapshot

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May 18, 2011

1 snapshot

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May 25, 2011

1 snapshot

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Jun
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June 3, 2011

1 snapshot

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June 9, 2011

1 snapshot

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June 15, 2011

1 snapshot

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June 21, 2011

1 snapshot

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June 22, 2011

1 snapshot

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June 23, 2011

1 snapshot

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June 30, 2011

1 snapshot

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Jul

July 1, 2011

1 snapshot

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July 4, 2011

1 snapshot

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July 6, 2011

1 snapshot

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July 7, 2011

1 snapshot

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July 13, 2011

1 snapshot

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July 15, 2011

1 snapshot

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July 20, 2011

2 snapshots

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July 25, 2011

2 snapshots

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July 28, 2011

1 snapshot

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Aug
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Sep
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Oct
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Nov
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Dec
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Note

This calendar view maps the number of times http://www.nhpco.org/ was crawled by the Wayback Machine, not how many times the site was actually updated. More info in the FAQ.