Public Datasets With Interesting Patterns In NULL/missing Data

I’m working on a project focused on missing data. Does anyone know of interesting datasets with the following criteria?

Publicly available for download, in a tractable format Data arrives over time (e.g. a new batch every day/week/month; or at least new rows added from time time time.) Some columns have missing values Ideally, missing values show interesting patterns of some kind (e.g. “column X is sometimes missing when column Y == A, but never when column Y == B” or “percentage of missing values in column Z is much higher on weekends.”

I’m willing to wade through a fair amount of EDA to find interesting patterns. Really, anything you can point me to would be helpful.