Masks correlation with coronavirus cases and deaths in US states

I ran an analysis that compares the date of mask mandates with cases and deaths for coronavirus. No statistical analysis, but the charts and output strongly suggest a correlation

Script output:

cases_total_before 0.16330318584574205
cases_total_after  0.11865204705545934
death_total_before 0.00608007236280604
death_total_after  0.003947986949385576

Charts:

• Averages: https://i.imgur.com/zMoutEQ.png
• Averages + each state in background: https://i.imgur.com/LjbnYbG.png

link