Correct. However, I've just realized thanks to the link from u/denisrennes that the 1975 Banqiao Dam failure article gives an upper estimate of 240,000 deaths while the List of Accidents and Disasters by Death Toll page listed a single 171,000 figure. I use the past tense here because I just edited the page with a correction.

Regardless, the visualization rounds all figures (as stated in the image and my top-level comment) so both 171,000 and 240,000 would result in the same 2 squares being shown.