Which of the following statements regarding "Six Sigma" is TRUE?

The term has two distinct meanings$-$one is statistical; the other is a comprehensive quality system.

Six Sigma means that about $94$ percent of a firm's output is free of defects.

The Six Sigma program was developed by Toyota in the $1970s.$

The Six Sigma program is for manufacturing firms and is not applicable to services.

Six Sigma certification is granted by the International Standards Organization $($ISO$).$