U.S.NationalChampionYears

Given a predicate that represents a relationship or action between entities, generate a one-sentence description explaining its meaning.  
# Instructions
Focus on describing the relationship, not the entities themselves. 
# Response Format
Begin the description with \' Indicates...\'

Predicate: U.S.NationalChampionYears

Indicates the years in which an entity held a U.S. national champion title in a particular sport or competitive field.