Data

Each value in B is the amount that the Federal Reserve balance sheet changed for a given week.

Largest drop since...

This past week, the balance sheet decreased by $31,617.

This is the largest drop since Dec 29th.

These values are highlighted in the data above.

Question

It would be nice to have a column that calculates this for us. I.e. something like weeks since larger drop.

Example with the last 4 manually filled out:

So, on 2022-05-25 when the balance sheet dropped $31,617, it was the biggest drop since 2021-12-29. And it had been 21 weeks since that larger drop.

What's a good way to have a formula that calculates these extra columns?

Logic

Seems like the logic should be:

• Search backward for the lower value
• Get the date at that row
• Compute date diff. Find number of weeks from that.

Link to sheet

Here's a link to the google sheet shown above, in case you'd like to experiment on the data.