College Board publishes average scores for the SAT every year. In 2015, the average score was 1490 out of 2400, with subject test scores of 495 for critical reading, 511 for mathematics and 484 for writing. Students who achieve a score of 1550 are considered "college and career ready."
The Commonwealth Foundation publishes average SAT scores by state. In 2014, the most recent year for which data is available, North Dakota had the highest average SAT score with 1816 points. In contrast, Washington, D.C. had the lowest average SAT score with only 1309 points. PrepScholar lists SAT scores by year, starting in 1972 and ending in 2014. Mathematics scores have improved in that time period, from 509 to 513, while critical reading scores have dropped from 530 to 497.