Steps to reproduce:

1. Edit a graph widget in a dashboard
2. In tab "Displaying options" check "Percentile line (left)", set value to 1
3. Observe percentile line added on your graph

Result: label of the line says "1th percentile: xxx", all percentage labels end in "th" no matter the number.
Expected: label should say "1st percentile: xxx". Same with 2th and 3th, should be 2nd and 3rd. Accordingly all percents that end in 1, 2 or 3 should be corrected, e.g., 91st, 92nd, 93rd etc.

Same incorrect ordinal forms are displayed in a host graph's legend.