Every kid grew up using Crayola crayons at school.
If you were a kid during the 1970s or 80s, you probably got to play with a box filled with 72 colors.
Turns out Crayola has been adding new colors to the box periodically every decade or so. From the humble origins of only 8 crayons back in 1903, the total today is 128!
Here is a chart showing the evolution of the crayon container. At the current growth rate of 2.56% per year, the crayon box doubles every 28 years!