The first half of the week 18 August - 24 August 2019 comes in at 409.66 ppm (NOAA) and 409.94 ppm (Scripps). If the week ended today, this would be an increase of 2.76 ppm/yr and 3.01 ppm/yr, respectively.
20 August 2019 was a low value, 409.1 ppm, over 1 ppm below the previous days. This is similar to what happened around 28 July 2019. In 2018, the measurements decreased during the second half of the week. If daily values in 2019 recover to above 409.8 ppm, a yearly increase of above 3 ppm is within reach.
We are about six weeks from the yearly minimum, which last year was around 405.5 ppm.
Enjoy the below-410 values while they last. After December, we will never seen those again.