diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 2784b04..31dd2e3 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -12,7 +12,7 @@ repos:
 
 # Run ruff to lint and format
 -   repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.7.2
+    rev: v0.8.1
     hooks:
     # Run the linter.
     -   id: ruff
diff --git a/powerplantmatching/plot.py b/powerplantmatching/plot.py
index 7a10b4f..d1d77b7 100644
--- a/powerplantmatching/plot.py
+++ b/powerplantmatching/plot.py
@@ -304,7 +304,7 @@ def boxplot_gross_to_net(axes_style="darkgrid", **kwargs):
         ax2 = ax.twiny()
         ax2.set_xlim(ax.get_xlim())
         ax2.set_xticks([i + 1 for i in range(len(dfg))])
-        ax2.set_xticklabels(["$n$=%d" % (len(v)) for k, v in dfg])
+        ax2.set_xticklabels([f"$n$={len(v)}" for k, v in dfg])
         fig.suptitle("")
         return fig, ax