Tariff timeline with China, so far

The U.S. and China put a semi-hold on tariffs for the next 90 days. The New York Times provides the timeline so far.

Tariffs on Chinese goods are down to 30% from 145% and tariffs on U.S. goods are down to 10% from the retaliatory 125%. Has anyone explained how countries choose these numbers? They seem arbitrary.

In any case, I’m guessing these step charts will need to update a few times over the next few months. Step charts, which show constant values and then sudden changes over time, might be the chart type of the next few years.

Chart Type Used

Step Chart