According to the NOAA report Carbon dioxide levels rose at record pace for 2nd straight year (graph here from their report).
“The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last Ice Age,” Tans said. “This is a real shock to the atmosphere.”
Globally averaged CO2 levels passed 400 ppm in 2015 — a 43-percent increase over pre-industrial levels. In February 2017, CO2 levels at Mauna Loa had already climbed to 406.42 ppm.
NOAA provides an interactive website with data: Trends in Atmospheric Carbon Dioxide. The calculus materials page here also has Mauna Loa CO2 data and a project.