Plotting monthly atmospheric CO2 concentrations over time

Hello,
I have 3 columns of data - year, month and atmospheric CO2 (ppm).
The first 3 years look like this to give you an idea.

1960 1 316.43
1960 2 316.97
1960 3 317.58
1960 4 319.02
1960 5 320.03
1960 6 319.59
1960 7 318.18
1960 8 315.91
1960 9 314.16
1960 10 313.83
1960 11 315
1960 12 316.19
1961 1 316.93
1961 2 317.7
1961 3 318.54
1961 4 319.48
1961 5 320.58
1961 6 319.77
1961 7 318.57
1961 8 316.79
1961 9 314.8
1961 10 315.38
1961 11 316.1
1961 12 317.01

How do I plot it so year is on the x-axis, ppm on the y-axis, and the monthly fluctuations are seen on the scatter graph so it ends up looking like the Keeling curve? http://en.wikipedia.org/wiki/Keeling_Curve

I hope that's clear, any help very much appreciated!

You are an absolute genius thank you so much!