Input (grade 5): At the time, the world population stood at 5.5 billion, and low-bound scenarios predicted a peak of 7.8 billion by 2050, a number that current estimates show will be reached around 2022.
Output (grade 6): At the time, the world population stood at 5.5 billion, and optimistic scenarios predicted a peak of 7.8 billion by 2050, a number that current estimates show will be reached around 2030.