[0] and [3] are current-dollar (i.e. not inflation adjusted). Easy to calculate, but rather difficult to evaluate (in terms of purchasing power) with a figure 60 years later.

[2] is inflation adjusted. Methodologies for that can vary quite a bit (other inflation adjustment sites give a value >$20K) but the result is a more meaningful comparison.

I have no idea what [1] is supposed to be, and they don't seem to be giving any sources or listing any methodology.