The pitches to which the phrase "all the years" is sung span nearly an octave (C Bb D). Because of this breadth and because these are three different pitches, there's a sense of the entirety of that "all."
On a smaller scale, this feature is also present with the phrase "all the earth" (A G F) at the end of the second verse: "And praises sing to God the king / And peace to all the earth!"