To answer your first question about percentage amount: The third line for 1990-2000 (35-50%) was turned into 40-60%, while the forth line for 2000-present (50-75%)] was turned into 60-80%. So we still have equal amounts overall. 
To answer your second question: We currently don't have [Page 2] anymore, it was created at one point but it was re-merged with the original. And the main reason we decided to trip the bottom 20 million is because the list had passed 350,000 bytes. For many months ahead, we won't be modifying the length of the list. And we may never will if we manage to keep the bytes around 250,000.