diff --git a/runtime/src/bucket_map_holder_stats.rs b/runtime/src/bucket_map_holder_stats.rs
index 26662fcd69..08df6c2f02 100644
--- a/runtime/src/bucket_map_holder_stats.rs
+++ b/runtime/src/bucket_map_holder_stats.rs
@@ -38,16 +38,19 @@ pub struct BucketMapHolderStats {
     pub active_threads: AtomicU64,
     pub get_range_us: AtomicU64,
     last_age: AtomicU8,
+    last_ages_flushed: AtomicU64,
     pub flush_scan_update_us: AtomicU64,
     pub flush_remove_us: AtomicU64,
     pub flush_grow_us: AtomicU64,
     last_was_startup: AtomicBool,
     last_time: AtomicInterval,
+    bins: u64,
 }
 
 impl BucketMapHolderStats {
     pub fn new(bins: usize) -> BucketMapHolderStats {
         BucketMapHolderStats {
+            bins: bins as u64,
             per_bucket_count: (0..bins)
                 .into_iter()
                 .map(|_| AtomicU64::default())
@@ -82,17 +85,23 @@ impl BucketMapHolderStats {
     }
 
     fn ms_per_age<T: IndexValue>(&self, storage: &BucketMapHolder<T>, elapsed_ms: u64) -> u64 {
-        if !storage.get_startup() {
-            let age_now = storage.current_age();
-            let last_age = self.last_age.swap(age_now, Ordering::Relaxed) as u64;
-            let mut age_now = age_now as u64;
-            if last_age > age_now {
-                // age wrapped
-                age_now += u8::MAX as u64 + 1;
-            }
-            let age_delta = age_now.saturating_sub(last_age) as u64;
-            if age_delta > 0 {
-                return elapsed_ms / age_delta;
+        let age_now = storage.current_age();
+        let ages_flushed = storage.count_ages_flushed() as u64;
+        let last_age = self.last_age.swap(age_now, Ordering::Relaxed) as u64;
+        let last_ages_flushed = self.last_ages_flushed.swap(ages_flushed, Ordering::Relaxed) as u64;
+        let mut age_now = age_now as u64;
+        if last_age > age_now {
+            // age wrapped
+            age_now += u8::MAX as u64 + 1;
+        }
+        let age_delta = age_now.saturating_sub(last_age) as u64;
+        if age_delta > 0 {
+            return elapsed_ms / age_delta;
+        } else {
+            // did not advance an age, but probably did partial work, so report that
+            let bin_delta = ages_flushed.saturating_sub(last_ages_flushed);
+            if bin_delta > 0 {
+                return elapsed_ms * self.bins / bin_delta;
             }
         }
         0 // avoid crazy numbers