After mortgage interest rates dropped to their lowest year-to-date level last week, Black Knight estimates that a total of 8.2 million U.S. borrowers could now lower their current loan rates by 0.75% or more if they refinanced. That represents an increase of 6.3 million since November 2018 when rates topped 5%. Black Knight says that up to 35% of those who took out mortgage loans last year could see significant savings by refinancing at today’s rates.