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Even though all things defined in your chart are called definition, there are generally five main categorizations of definition. They have to do with the channels and centers only.

The five definitions are: Single, Split, Triple Split, Quadruple Split and No Definition. This relates to what centers are connected to each other. For example, you are a single split if all your defined centers are connected. You are a split definition if you have one set of defined centers that are connected but they are not connected to another set of centers.

Single - 41%

Split - 46%

Triple - 11%

Quadruple - >1%

None - >2%

Percentages

Split definition is the most common definition, with 46% of the population. After that is single definition with 41%. Triple splits are a considerably smaller percentage of the population with 11%. People with no definition (reflectors) range at just below 2%. Quadruple split people are very rare, with less that 1% of the population.

credit: Jovian