Today only about 21 percent of americans

21 percent of Americans report personal experience with medical errors

Explanation:

1. Special tribunes would represent the plebeians.
2. The Plebeian Council could pass laws that applied to plebeians.

"Tribunis Plebis" was the Latin term for "Tribune of the people" (the plebs).
"Concilium Plebis" was the Latin name for the Plebeian Council or assembly.

There had been assemblies of the plebeians before 494,  but after that date the assembly's actions, under the authority of the tribune of the people, carried more official authority.  The creation of the office of tribune, to represent the people and offset the power of the consul, occurred after major conflict between the plebeians and the ruling class (the patricians) in 495-494.