diff --git a/iiif/utils.py b/iiif/utils.py
index bb54f37..f74e061 100644
--- a/iiif/utils.py
+++ b/iiif/utils.py
@@ -290,7 +290,7 @@ def pct(self) -> str:
 
         :return: the percentage the cache is in use as a formatted string
         """
-        return f'{(self.total_size / self.max_size):.2f}%'
+        return f'{((self.total_size / self.max_size) * 100):.2f}%'
 
     def _clean_up(self, path: Path):
         """
@@ -361,7 +361,11 @@ async def use(self, fetchable: Fetchable) -> Path:
             elif not path.exists():
                 async with self._locker.acquire(path, timeout=self.fetch_timeout):
                     if not path.exists():
-                        await self._fetch(fetchable)
+                        try:
+                            await self._fetch(fetchable)
+                        except Exception:
+                            self.errors += 1
+                            raise
                         self._sizes[path] = path.stat().st_size
                         self.total_size += self._sizes[path]
 
diff --git a/setup.py b/setup.py
index 38890de..d15e192 100644
--- a/setup.py
+++ b/setup.py
@@ -36,7 +36,7 @@
 
 setup(
     name="iiif-image-server",
-    version='0.10.0',
+    version='0.12.1',
     author='Natural History Museum',
     author_email='data@nhm.ac.uk',
     description="A media server primarily used by the NHM Data Portal",