Add validation/constraint for statewide incarceration rate calculation

[nasaownsky]

Description of the change

1. Fixed counties reporting caption in graph tooltip to match #99 requirements.
2. Added arbitrary floor (10% population covered) as validation to statewide graph

Type of change

• [ ] Bug fix (non-breaking change that fixes an issue)
• [x] New feature (non-breaking change that adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Configuration change (adjusts configuration to achieve some end related to functionality, development, performance, or security)

Related issues

Closes #100

Checklists

Development

These boxes should be checked by the submitter prior to merging:

• [x] Manual testing against realistic data has been performed locally

Code review

These boxes should be checked by reviewers prior to merging:

• [x] This pull request has a descriptive title and information useful to a reviewer
• [x] This pull request has been moved out of a Draft state, has no "Work In Progress" label, and has assigned reviewers
• [x] Potential security implications or infrastructural changes have been considered, if relevant

[nasaownsky]

@colincadams Check the latest changes and approve if they're right.

[colincadams]

I don't think there is any fixture data that works with the 10% threshold unfortunately, but the last point for CO only covers 25% and the rest cover more so I upped the threshold to 30% to test.

before:

after:

It looks to me like instead of dropping the last incarceration rate point as expected, it instead just shifted the line one month to the left. I also think we will want this to affect both key insights and the charts (@hobuobi ?)

[nasaownsky]

@jessex as @colincadams noted testing can only be performed with manual changing either threshold level or percentage_covered_population in jails fixture file. @colincadams I've fixed that bug!

[jessex]

@colincadams would you mind taking over review for this one since you've already got a handle on it? Thanks!

[nasaownsky]

@colincadams About implementation. If, for example, latest displaying rate has constraint, all key insights should display data month back? Or just rate?

[colincadams]

@nasaownsky that is a great thought! Discussed with @hobuobi and we agree it makes sense to limit all key insights based on the percentage covered for incarceration rate. So if the constraint applies for a particular month, all statewide data for that month should be dropped.

[nasaownsky]

@colincadams Could you include percentage_covered_population field in PERCENTAGE_COVERED_COUNTY metric in jails fixture file?

[colincadams]

I can add that, and then you could limit both INCARCERATION_RATE_JAIL and PERCENTAGE_COVERED_COUNTY based on their own percentage_covered_population field, but you would still have to limit POPULATION_JAIL based on the percentage_covered_population of one of the other two metrics since it will have it's own value that may be different. In that case is it still useful to add the field to PERDCENTAGE_COVERED_COUNTY?

[nasaownsky]

@colincadams sorry for bother you, I managed to add constraint without any new data. Check this out.

[colincadams]

Not a bother at all, thanks for helping us think through the edge cases here! This seems to be working well now, and I think the approach is reasonable. Thanks for fixing the problem when percentage covered was null also!

Posting screenshots to capture the behavior change: