By Martin Baccardax A key indicator of Treasury bond demand slumped lower Monday as investors shied away from a $32 billion auction on the eve of August inflation data. The U.S. Treasury sold $35 billion in 10-year notes Monday at a high auction yield of 3.33%, although bidders shied-away from the re-opened issue that comes just ahead of a key reading of August inflation. Investors bid $2.37 for every $1 of 10-year notes on offer from the Treasury, auction data indicated, a notably softer tally than the 2.57 ‘bid-to-cover’ ratio recorded at the last auction on August 10, when the yield was jus…