The worl population is the total number of living humans on Earth at a given time. As of May 2008, the world's population is believed to be just over 6.7 billion. In line with population projections, this figure continues to grow at rates that were unprecedented before the 20th century, although the rate of increase has almost halved since its peak, which was reached in 1963, of 2.2 percent per year. The world's population, on its current growth trajectory, is expected to reach nearly 9 billion by the year 2042.