I think they set a limit on how far back it can go... but I remember the first time ONE showed up on my threat list back in the 300s, he was gaining like 0.24 points per day and had a long way to go... he was scheduled to pass me in 90 years or something crazy. I think it was 2090.
For instance, earlier this afternoon, Nikhsub1's total 7-day points were like 12,700 and Erpauls were something like 12,715. So technically, he should have shown up on Nik's threat-list... but he wasn't because at 15 points gained per day, 200,000 points would take 36 years to pass him. I haven't seen anything that high in a long time. The best lately was erpauls > nik at 2028 (25 years) so maybe that's the limit? 25 years? Shrug...