Just checked my spreadsheet...
I compute two metrics for hit-percentage:
1. Compute hit-percentage for every "test", each test has 20 questions - let's call this
20HIT
2. Compute hit-percentage for every 100 questions (or every 5 tests) - let's call this
100HIT
I only completed 480 questions from SC1000.
1st 100 questions:
20HIT range from 50% to 65%
100HIT is 61%
2nd 100 questions:
20HIT range from 55% to 65%
100HIT is 60%
3rd 100 questions:
20HIT range from 55% to 75%
100HIT is 64%
4th 100 questions:
20HIT range from 65% to 85%
100HIT is 71%
Last 80 questions:
20HIT range from 65% to 90%
100HIT is 59%
In general the variation is still high between test sets. However, you can see both the low- and high- end ranges are both improving.
Note that I cut-and-paste all my wrong questions to a separate Word file and re-do those questions. My hit rate is approximately 50% for re-do questions (I make sure I don't remember the answers).