Numbers don't tell the whole story

It is not the statistical frequency or infrequency that makes the initial placement of adverbials special, but the cognitive processing function that they accomplish in this position. In each case, the nonfocal element provides an explicit frame of reference for the clause that follows. It is not the most important part of the clause (i.e., focal), instead it sets the stage for the clause that follows by establishing a specific state of affairs or context for relating the clause that follows to the previous context.—Discourse Grammar of the Greek New Testament, page 227