But Soft! What Light Through the Yonder Window Breaks?

Here is a small portion of a visualization titled "Chart of the proportions of rhyme, blank verse, and prose in Romeo and Juliet". (http://www.twelfth-night.info/clicknotes/romeo/Chart.html). This perspective of the play is interesting to look at because you can compare the composition of each act and scene and ponder what motives Shakespeare had for using rhymes or proses.

Of course there is nothing that can be done except speculate; did Shakespare simply feel like using about 14% (26 lines) rhyme in Act II Scene II, and then 100% (94 lines) rhyme in Act II Scene III? Or is it because the famous balcony scene is Act II Scene II, and thus the following scene is a fantasy world full of rhyme because Romeo is high from his moonlit meeting with Juliet?