Overall ratings:

Score range	Grade	Level
0-74	D	Low
75 - 149	DD	Low
150 - 224	DDD	Low
225 - 299	C	Low
300 - 449	CC	Low
450 - 599	CCC	Low
600 - 749	B	Medium
750 - 899	BB	Medium
900 - 1199	BBB	High
1200 - 1799	A	High
1800 - 2699	AA	Excellent
2700 - 3000	AAA	Excellent