U.S. rates of uncontrolled hypertension have remained stagnant for half a decade, while overall prevalence hasn’t changed since the late '90s, the Centers for Disease Control and Prevention (CDC) reported in its most recent National Health and Nutrition Examination Survey (NHANES).

Prevalence of high blood pressure has increased steadily with age for more than a decade, the CDC said in its report, but the younger a hypertensive patient is, the less likely they are to control the condition. The latest CDC numbers, drawn from data pulled between 2015 and 2016, put hypertension rates in the U.S. at 29 percent—not a significant change from previous years. Of those cases, just under half—48.3 percent—are classified as controlled hypertension.

For the purposes of this study, the CDC defined hypertension as systolic blood pressure greater than or equal to 140 mmHg, or diastolic blood pressure greater than or equal to 90 mmHg. Controlled hypertension equates to blood pressure under 140 mmHg or 90 mmHg in those who have been diagnosed as hypertensive.

In its 1999-2000 results, the CDC reported in NHANES that controlled hypertension among American adults was around 32 percent. That number leapt to 53 percent in 2009-2010, but aside from that jump, rates have stayed relatively steady since then.

More than 63 percent of adults 60 years or older live with high blood pressure, the CDC wrote, and just over 33 percent of 40- to 59-year-olds live with the condition. In a younger demographic, between 18 and 39 years old, hypertension was less common at under 8 percent, but also less controlled—15.5 percent of men in that group had managed hypertension, compared with 62.6 percent of women.

This year’s report ranked black men and women as the populations with the greatest rates of hypertension. Hispanic women were more likely than Asian women to have high blood pressure, but controlled hypertension as a whole was more ubiquitous among white men and women than in black and Asian groups. In all populations, controlled hypertension was more prevalent in women than in men.

The results of this NHANES cycle threaten the country’s upcoming “Healthy People 2020” goal, which aimed to increase controlled hypertension to 61.2 percent by 2020. Now, with just under half of all hypertensive adults managing their symptoms, the U.S. is lagging behind its goal by nearly 13 percent.

“Hypertension remains an important public health challenge in the United States because it increases the risk for cardiovascular disease,” the NHANES authors wrote. “Effective blood pressure management has been shown to decrease the incidence of stroke, heart attack and heart failure.”

Read the rest of this year’s NHANES report here.