Based on the January 13th weekly report, Chelsea has an average daily case rate of 538.3 per 100,000 residents and 29.7% of tests coming back positive. More stats...
7-day case rate: 665.6 per 100K daily
14-day case rate: 538.3 per 100K daily
Cases to date: 13,618 (36.9% of residents)
Population: 36,918 (est.)
Daily New Cases per 100,000
(averaged over prior two weeks)
The bar chart values come directly from the MA DPH's weekly report, specifically the "Average Daily Incidence Rate per 100,000 (Last 14 days)" column. While far from perfect, this is one way to better compare data across towns since it factors in the population size. Think of it like a percentage, but instead of per 100, it's per 100,000.
Similarly, the dashed line comes from the "Percent Positivity (Last 14 days)" column and represents the level of tests coming back positive.
All bar colors are calculated using an old formula from the MA Dept of Health, which looks at population size, case counts, case rates, and positivity rates. Don't read too much into these.
Weekly New Cases
These chart values are derived from Chelsea's changes in "Total Case Count" from the prior week. It's not an exact science, due to reporting delays and occasional corrections.
Updated January 13, 2022