; and (3) by adding at the end the following: (3) State enrollment rates During each of fiscal years 2019 through 2023, to the maximum extent practicable, the Secretary shall carry out this subchapter in such a manner as to enroll and maintain acreage in the conservation reserve in accordance with historical State enrollment rates, considering— (A) the average number of acres of all lands enrolled in the conservation reserve in each State during each of fiscal years 2007 through 2016; (B) the average number of acres of all lands enrolled in the conservation reserve nationally during each of fiscal years 2007 through 2016; and (C) the acres available for enrollment during each of fiscal years 2019 through 2023, excluding acres described in paragraph (2). (4) Frequency In carrying out this subchapter, for contracts that are not available on a continuous enrollment basis, the Secretary shall hold a signup not less often than once every other year. . (c) Duration of contract Section 1231(e) of the Food Security Act of 1985 ( 16 U.S.C. 3831(e) ) is amended to read as follows: (e) Duration of contract (1) In general Except as provided in paragraph (2), for the purpose of carrying out this subchapter, the Secretary shall enter into contracts of not less than 10, nor more than 15, years. (2) Certain continuous contracts With respect to contracts under this subchapter for the enrollment of land described in paragraph (4) or (5) of subsection (b), the Secretary shall enter into contracts of a period of 15 or 30 years. . (d) Eligibility for consideration Section 1231(h) of the Food Security Act of 1985 ( 16 U.S.C. 3831(h) ) is amended— (1) by striking On the expiration and inserting the following: (1) In general On the expiration