About the Internal Loop Statistics page:

Internal loop statistics are available for subsequences of 3, 4, or 5 bases. These subsequences may be parts of internal loops of lengths specified in the columns of the table. The user may specify internal loops on 5' or the 3' half of the surrounding helix.

Alignment
# of Nucleotides: 3 nt 4 nt 5 nt
Location in Helix: 5' Half 3' Half