A company used 7 sales persons working 160 hours each month for 12 months to sell 70 cabinets, 700 tables and 7000 chairs during the year 2021. In 2022, the company used 6 sales persons working 190 hours each month for 12 months to sell 65 cabinets, 500 tables and 8000 chairs. In 2021, the company earned revenue of $800 for each cabinet, $200 for each table and $50 for each chair. In 2022, the price of each item went up by 7%. Find the sales force productivity in $ per hour for each year and then calculate the percentage change in productivity