That linked data is collected from local American races. The winner is overwhelmingly the person who won the first round, which is the only round the majority of the time. When people claim RCV will break the two party system they are trying to claim it will change the winners. The evidence largely shows that no voting system can take a single-winner duopoly and break it.
Any new voting system would require only a simple bill from the legislature. “Ballots instructions for every election at every level shall direct voters to select any number of candidates. The candidates with the most votes wins their respective election.”