Brian Phillips at Pats Pulpit compiled a butt ton of contract data, bucketing each contract based on size. He did not include rookie contracts or other ‘fixed’ contracts. Here’s some of the details on what he did.
Patriots bolster their league-leading “middle class” with David Andrews’ extension - Pats Pulpit
If the goal is to establish which teams are truly making the decisions to pay players above the CBA-mandated minimums based on their NFL experience (or more technically stated, their amount of credited seasons), then you must you filter out contracts for which the team had no choice but to invest that dollar amount in the player.