Below are some animations depicting tracks (locations) of aircraft data from various dates.
Notice the difference in in data/observations from aircraft before the COVID-19 pandemic hit (June 30 - July 1st 2019; Figure 1 below) and during the pandemic (April 13th & 27th 2020; Figure 2 and 3, respectively).
There is a drastic reduction in tracks during the pandemic - especially in the midst of stay-at-home ordinances on April 13th.
Figure 1. Observations from aircraft, June 30 to July 1, 2019.
Figure 2. Observations from aircraft, April 13, 2020.
Figure 3. Observations from aircraft, April 27, 2020.