Saved assurance values not being displayed

Previously saved assurance values for two questions on this page were not being retained when editing the answers to the page.
Saved assurance values not being displayed (Page 39)

Assurance values were not being saved at all for this question.
Pricing interval dropdown did not always display correct saved value

Fixing my previous copy-and-paste FAIL. I blame the reviewer.
Merge pull request #170 from alphagov/kk_data_save_bugs

Data save & re-display bugs