Track the positivity rates for Illinois' 11 regions, plus Indiana northwest region (which borders the greater Chicago area), over the most recent two-week period. These rates are all based on moving seven-day averages for each region. For reference, if a region has a positivity rate of 12.0%, for example, that means that 12 out of every 100 people tested, tested positive for coronavirus. The World Health Organization advises that an area's positivity rates be at or under 5.0%. The State of Illinois begins issuing warnings, if an area is at or above 8.0%. Positivity rates of 10.0% and above are considered high, by nearly all health authorities.