http://www.math.neu.edu/~suciu/courses_nbr.html has been crawled 60 times going all the way back to August 23, 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
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

January 16, 2011

2 snapshots

16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Feb
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

February 16, 2011

2 snapshots

16
17
18
19
20
21
22
23
24
25
26
27
28
Mar
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Apr
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

April 20, 2011

4 snapshots

20
21
22
23
24
25
26
27
28
29
30
May
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

May 23, 2011

2 snapshots

23
24

May 25, 2011

1 snapshot

25
26
27
28
29
30
31
Jun
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

June 23, 2011

2 snapshots

23
24
25
26
27
28
29
30
Jul
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

July 16, 2011

1 snapshot

16
17
18
19
20
21
22

July 23, 2011

2 snapshots

23
24
25
26
27
28
29
30
31
Aug
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Sep
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Oct
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Nov
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Dec
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

Note

This calendar view maps the number of times http://www.math.neu.edu/~suciu/courses_nbr.html was crawled by the Wayback Machine, not how many times the site was actually updated. More info in the FAQ.