Scoring World History test

How many raw points do you need on the World History subject test to get an 800 and also to get a 700?

World History: 95 questions
-18: 800
-19/20:790
-21: 780
-22/23: 770
-24/25: 760
-26: 750
-27/28: 740
-29/30: 730
-31/31: 720
-32: 710
-33/34: 700

if you leave 18 answers blank, you get an 800.

Thank you!