Which one of the following is the correct percentage of the two (out of the total of 4) green-house gases that contribute to the total global warming?

The gases, which are transparent to solar radiation but retain and partially reflect back long wave heat radiations are called green-house gases. Recently, the concentration of green-house gases has started rising resulting in enhanced green-house effect that is resulting in increase the mean global temperature. It is called global warming. The various green house gases are $\mathrm{CO}_2$ (warming effect $60 \%), \mathrm{CH}_4(20 \%)$, CFCs (14\%) and nitrous oxide- $\mathrm{N}_2 \mathrm{O}(6 \%)$.