DES MOINES — More than 40 percent of confirmed coronavirus cases in Iowa were among children and people in their 20s, according to state data released Wednesday.

The state, which currently updates its data once a week, reported an additional 8,907 new positive cases and 29 additional deaths to bring the state’s total to 6,307. The seven-day rolling average of cases has been gradually increasing since early June and is now at 8,225 cases per week, a level not seen since January.

The data shows that 22 percent of the positive tests in the last week were among children 17 and younger and 20 percent of positives were among those in their late teens and 20s.

Some northern Iowa counties with high positivity rates are reporting more than one-third of their new positive cases are among children under 17. In Crawford County, 44 percent of the cases in the past week were among that age group and in Floyd county it was 40 percent. In Story County, the home of Iowa State University, 40 percent of new COVID-19 cases were reported among the 18 to 29 age group.

Iowa has vaccinated 51.8 percent of its population, according to the Centers for Disease Control and Prevention, ranking the state 23rd in the nation.