"This notice provides guidance on the corporate bond monthly yield curve (and the corresponding spot segment rates), and the 24-month average segment rates ... In addition, this notice provides guidance as to the interest rate on 30-year Treasury securities ... as in effect for plan years beginning before 2008, the 30-year Treasury weighted average rate ... and the minimum present value segment rates ... as in effect for plan years beginning after 2007. These rates reflect certain changes implemented by ... MAP-21 [which] provides that for purposes of section 430(h)(2), the segment rates are limited by the applicable maximum percentage or the applicable minimum percentage based on the average of segment rates over a 25 year period."