Between 2005 and 2015 the maximum score was 2400 instead of 1600. Assuming anyone who got <1600 during that period wouldn't admit it, you now have three well defined buckets.

But of course this is a lot of unnecessary steps compared to the usual method: length of work and education history +18 years.

The extra 800 points didn't count for a few years, I didn't practice for it and as expected did bad. Don't remeber the score except I did well enough on math