Do not understand THD %

Sep 2017
I am trying to figure out the following

individual minimum current harmonics of 75% at the 3rd,
50% at the 5th,
and 25% at the 7th

I am trying to reproduce these waveforms on a ATX power supply at 3A DC load. I know that 100% THD is when its a pure sinewave, 25% would be something like a sawtooth waveform. Does this seem right?