Full scan of March 2020 - are people self isolating for COVID-19?

Extract just March's data, then import it to the database:

grep -E "^2020-03" tcpdump.log > /tmp/march.wifi.log
php trim.php /tmp/march.wifi.log > march-trimmed.csv

Raw data for March was 21Gb, approx 168 million lines.

Then import to the mySQL database:

LOAD DATA INFILE 'march-trimmed.csv' INTO TABLE wifi_data;