After a drop last year, Louisiana's public high school graduation rate shot up to 78.1 percent, the state's highest ever, officials announced Thursday.

The latest figure, which applies to the Class of 2017, is up from 77 percent for the Class of 2016.

Even with the increase the state rate is expected to remain well below the national average, which was 84 percent for the Class of 2016, the latest figure available.

"We know our graduation rate needs to be better," state Superintendent of Education John White told reporters.

High school graduation rates matter because they are a key barometer of a state's education achievement. While among the lowest in the nation, Louisiana's high school graduation rate has bounced around in recent years. It rose by four percentage points between 2013-15, then dropped last year.

A total of 39,370 public school students graduated in Louisiana last year, an increase of 511 students from the previous year and over 3,000 more than the Class of 2013, according to the state Department of Education.

"The bottom line is not only is the state making progress but historically disadvantaged populations are also making progress at a rate that is greater than the state average," White said.

White has cautioned against reading too much into yearly results. The upward trend stems from policies launched in 2012, including changes in the state's accountability system, a requirement that students seek college financial aid even if they have no plans to attend and an overhaul in the state's career education program, he said.

The graduation rate for African American students is 72.8 percent, up from 71.5 percent last year.

Students from poor families had a rate of 72.6 percent, up from 71.3 percent last year.

The state's ambitious goal is to have a high school graduation rate of 90 percent by 2025, part of a push to increase academic rigor in public schools.

A 2009 state law required the state to reach an 80 percent graduation rate by 2014.

That law was largely symbolic.

White said that, while Louisiana has not reached the goal, setting it helped spur the state to make needed public school changes.

Officials cited a wide range of factors for graduation improvements.

A total of 48 percent of graduates earned college credit or career credentials, up from 43 percent the previous year.

Nearly 26,000 graduates earned the minimum ACT score needed for post-secondary training, up from about 25,000 in the Class of 2016.

The ACT measures college readiness.

More than 19,200 students qualified for some form of aid through the Taylor Opportunity Program for Students, up from 18,373 the year before.

White said he is hopeful turnaround plans that stem from the federal Every Student Succeeds Act will assist the state's most troubled public high schools.

Graduation rates include the East Baton Rouge Parish School District, 66.7, down 1.1; Ascension, 92.3, up 3.5; Livingston, 86.6, up 3.4; Lafayette, 76.8, up 1.8; West Baton Rouge, 74.3, down 3.4; Central, 88.4, up 2.4; Zachary, 91.1, up 2.1 and Baker, 61.7, up 1.2

The results show that some Baton Rouge schools that actually flooded in 2016 generally showed graduation gains. But other area schools affected by flooding had lower graduation rates, including Dutchtown High, Broadmoor High and Woodlawn High.

While the East Baton Rouge, West Baton Rouge and Pointe Coupee districts showed drops, others in the metro area gained, including the East Feliciana, Livingston, West Feliciana and Iberville school systems.

Scores for schools in East Baton Rouge Parish were mostly flat but some showed major drops, including Broadmoor High School, down 10.3 percentage points; Woodlawn, down 8.6, Northeast, down 6.2 and McKinley, down 4.

Lee High was a notable exception, rising from a graduation rate of 76.9 to more than 95 percent.

The gain coincides with Lee High becoming a dedicated magnet school housed in a new facility with a major expansion in its enrollment.

Charles Lussier of The Advocate contributed to this report

Follow Will Sentell on Twitter, @WillSentell.