Theymos announced the "Enhanced newbie restrictions & requirements" in post 45810047. This was on Sep 17 06:27 (Dutch time).

Post 44746501 was made 3 weeks (plus 60 minutes) earlier. In 3 weeks (+60 minutes) before the announcement, 1063546 posts were made. On average, in 3 weeks before the announcement, the forum saw 353,813 new posts per week. This is the number I'll use to compare results with.

Post 46096455 was made 1 week later.
Post 46376958 was made 2 weeks later.
Post 46636652 was made 3 weeks later.
Post 46900337 was made 4 weeks later.
Post 47140676 was made 5 weeks later.
Post 47380721 was made 6 weeks later.
Post 47600410 was made 7 weeks later.
That means:

• In the first week after the announcement, 286408 posts were made (-19.05%).
• In the second week after the announcement, 280503 posts were made (-20.72%).
• In the third week after the announcement, 259694 posts were made (-26.60%).
• In the fourth week after the announcement, 263685 posts were made (-25.47%).
• In the fifth week after the announcement, 240339 posts were made (-32.07%).
• In the sixth week after the announcement, 240045 posts were made (-32.15%).
• In the seventh week after the announcement, 219689 posts were made (-37.91%).