I found
the chart at agrimarketing.com. they got the info from Farm Journal.
This is the notation for the chart of market share.
Five Years of Seed Market Share: Company/brand consolidations and genetic performance continue to drive changes in seed market shares. One share point of seed corn in the U.S. market in 2014 (90.9 acres at 31,500 planting rate) represents 357,000 standard units of sales at an estimated retail value of $107 million. One share point of soybean seed in 2014 (84.2 million acres at 140,000 planting rate) represents 842,000 standard units of sales at an estimated retail value of $50 million.