These data are from NASS Quickstats. These rates are per acre, per year. However, lease terms are not specified, and leases for less than one year are included as well.  NASS will not publish 2018 rates and 2019 rates are not yet available.  More information is available here.

Kate Binzen Fuller
Assistant Professor
Extension Specialist
Department of Agricultural Economics and Economics
Montana State University
406-994-5603