When the Daily Dose of Septuagint went over the verse, I noticed that this division is given a bit more emphasis in the Septuagint.
πάντες ὡς πρόβατα ἐπλανήθημεν, ἄνθρωπος τῇ ὁδῷ αὐτοῦ ἐπλανήθη· καὶ κύριος παρέδωκεν αὐτὸν ταῖς ἁμαρτίαις ἡμῶν.
All we like sheep have gone astray; we have turned - every one - to his own way; and the LORD has laid on him the iniquity of us all. [ESV]
Because the same verb is repeated, first in the plural (ἐπλανήθημεν) and then in the singular (ἐπλανήθη), the transition from a group to individuals is more evident.