Taken from NOAA data starting in 1959.
1959-1969: 8.65 ppm
1970-1979: 11.1 ppm
1980-1989: 14.39 ppm
1990-1999: 13.98 ppm
2000-2009: 17.85 ppm
2010-2014: 8.7 ppm
There are those who say that it is the actual introduction of new CO2 into the atmosphere that causes the temperature to change. There are those who say that the concentrations play a larger role.
Whatever the case, concentrations are not only rising, they are rising more quickly than in the past.