Vertical spacing between different verses

[Simon Art]

Hi all,
I am musician, conductor. I just started with lilypond, and I like it very much.
I adapted the SATB vocal score template of the manual (Appendix D.4.1,  p. 292).

I want to change two things: 

1. Increase vertical spaces between the verses, i.e. the spaces between verse
one and two and between verse two and three. I want to do that for both the
soprano lyrics and the lyrics of the accompanying men's choir.

2. The vertical space between the staffs should stay as they are now.



Does anybody know what to do ?

Thank you very much

Simon Art