A 2007 Harris Poll of 1,010 U.S. adults suggested that occupational prestige is linked to perceived impact on community welfare, the highest ranking jobs being firefighter, scientists, and teachers. Lower ranking jobs include well-paid positions such as brokers, actors, and bankers. Police officers and engineers tended to fall somewhere in the middle of the ladder. According to The Harris Poll (2007), the following are the changes over the last quarter century of American's view as the most and least prestigious jobs: