How many Rubik's Cubes have been sold in 1974?

The Rubik's Cube was invented in 1974 by Hungarian architect Ernő Rubik, but it did not gain popularity until the late 1970s and early 1980s. By 1980, when it was officially launched worldwide, millions of units began to sell rapidly. Therefore, specific sales figures for 1974 are not readily available, as the cube was primarily a prototype and not commercially sold at that time.