It should be noted that the figures of bill/payment and advertising mail presented in Table 2 account only for the First-Class household mail and, thus, represent the lower bound of First-Class bill/payment and advertising mail volumes.
Table 2 only account for higher bounds of First-Class bill mail volumes. 
mnli hypothesis: Table 2 only account for higher bounds of First-Class bill mail volumes.  premise: It should be noted that the figures of bill/payment and advertising mail presented in Table 2 account only for the First-Class household mail and, thus, represent the lower bound of First-Class bill/payment and advertising mail volumes.