space between lyric lines

[John Bryant]

Hey lilypond users, 

My friend is creating hymns in their unicode non-roman script and they would like to increase the space a bit between the lines of lyrics. I saw that you can increase space between words but I couldn't find any command or instructions for increasing space between the whole lyric line with the next. 

I've included their files in case that helps.

THANKS,

JB

1 k 1 How Pleased and Blest Was I .ly
Description: Text Data

1 k 1 How Pleased and Blest Was I .pdf
Description: Adobe PDF document