笨。schools know those dropout , they donot even care.

US high school drop rate is sky high.

1. Every year, over 1.2 million students drop out of high school in the United States alone. That’s a student every 26 seconds – or 7,000 a day.
2. 
    
3. About a quarter of high school freshmen fail to graduate from high school on time.
4. 
    
5. The U.S., which had one of the highest graduation rates of any developed country, now ranks 22^nd out of 27 developed countries.
6. 
    
7. The dropout rate has dropped 3 percent from 1990 to 2010 (12.1 percent to 7.4 percent).