Which preposition to use with usque

in Occurrences 2%

22-29 (Salvum fac ... in aeternum) is considered by scholars to be simply versicles, responses and prayers; the verses 22-23 (Salvum fac... usque in aeternum).

at Occurrences 1%

E. Tantus est calor, quod virilia hominum exeunt corpus, et descendant usque at mediam tibiarum: ideo faciunt unctionum, et ungunt illa, et in, quibusdam sacculis ponunt circa se cingentes, et aliter morerentur.

Which preposition to use with  usque