I have some data (parts per million) where some of it is 1 or greater than one (but has an actual number.) However, some of the data simply lists "<1" ppm.
What is a good way to visualize this in a graph?
Should I pick an arbitrary decimal less than one, so that it can be shown on the graph? I feel setting it to zero would not be right either, as they went to the extent of listing it, so it must be significant.