diff --git a/src/benchmark/executor.rs b/src/benchmark/executor.rs
index e08774d..ac6577b 100644
--- a/src/benchmark/executor.rs
+++ b/src/benchmark/executor.rs
@@ -266,7 +266,7 @@ impl Executor for ShellExecutor<'_> {
             time_wall_clock: measurements.time_wall_clock_mean(),
             time_user: measurements.time_user_mean(),
             time_system: measurements.time_system_mean(),
-            peak_memory_usage: Information::zero(),
+            peak_memory_usage: measurements.peak_memory_usage_mean(),
             exit_status: ExitStatus::default(),
         });
 
diff --git a/src/benchmark/measurement.rs b/src/benchmark/measurement.rs
index 9eaa8d0..58d522c 100644
--- a/src/benchmark/measurement.rs
+++ b/src/benchmark/measurement.rs
@@ -1,7 +1,7 @@
 use std::process::ExitStatus;
 
 use crate::quantity::statistics::{max, mean, median, min, modified_zscores, standard_deviation};
-use crate::quantity::{second, Information, Time};
+use crate::quantity::{Information, Time};
 
 /// Performance measurements and exit status from running a single command
 #[derive(Debug, Default, Copy, Clone)]
@@ -77,12 +77,7 @@ impl Measurements {
 
     /// Compute modified Z-scores for the wall clock times.
     pub fn modified_zscores(&self) -> Vec<f64> {
-        modified_zscores(
-            &self
-                .wall_clock_times()
-                .map(|t| t.get::<second>())
-                .collect::<Vec<_>>(),
-        )
+        modified_zscores(&self.wall_clock_times().collect::<Vec<_>>())
     }
 
     /// The average user time.
@@ -94,4 +89,8 @@ impl Measurements {
     pub fn time_system_mean(&self) -> Time {
         mean(self.measurements.iter().map(|m| m.time_system))
     }
+
+    pub fn peak_memory_usage_mean(&self) -> Information {
+        mean(self.measurements.iter().map(|m| m.peak_memory_usage))
+    }
 }
diff --git a/src/command.rs b/src/command.rs
index 1fb5c0d..58bb830 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -97,10 +97,14 @@ impl<'a> Command<'a> {
         &self.parameters
     }
 
+    pub fn is_parameter_unused(&self, parameter: &str) -> bool {
+        !self.expression.contains(&format!("{{{parameter}}}"))
+    }
+
     pub fn get_unused_parameters(&self) -> impl Iterator<Item = &(&'a str, ParameterValue)> {
         self.parameters
             .iter()
-            .filter(move |(parameter, _)| !self.expression.contains(&format!("{{{parameter}}}")))
+            .filter(move |(parameter, _)| self.is_parameter_unused(parameter))
     }
 
     fn replace_parameters_in(&self, original: &str) -> String {
diff --git a/src/outlier_detection.rs b/src/outlier_detection.rs
index 422481a..e672c26 100644
--- a/src/outlier_detection.rs
+++ b/src/outlier_detection.rs
@@ -14,13 +14,13 @@ pub const OUTLIER_THRESHOLD: f64 = 1.4826 * 10.0;
 /// modified Z-score that is larger than `OUTLIER_THRESHOLD`.
 #[cfg(test)]
 pub fn num_outliers(xs: &[f64]) -> usize {
-    use crate::quantity::statistics::modified_zscores;
+    use crate::quantity::statistics::modified_zscores_f64;
 
     if xs.is_empty() {
         return 0;
     }
 
-    let scores = modified_zscores(xs);
+    let scores = modified_zscores_f64(xs);
     scores
         .iter()
         .filter(|&&s| s.abs() > OUTLIER_THRESHOLD)
diff --git a/src/quantity/statistics.rs b/src/quantity/statistics.rs
index 4065777..a0657a3 100644
--- a/src/quantity/statistics.rs
+++ b/src/quantity/statistics.rs
@@ -112,7 +112,7 @@ pub fn standard_deviation<Q: UnsafeRawValue>(values: &[Q], mean: Q) -> Q {
 ///
 /// References:
 /// - <https://en.wikipedia.org/wiki/Median_absolute_deviation>
-pub fn modified_zscores(xs: &[f64]) -> Vec<f64> {
+pub fn modified_zscores_f64(xs: &[f64]) -> Vec<f64> {
     assert!(!xs.is_empty());
 
     // Compute sample median:
@@ -131,6 +131,11 @@ pub fn modified_zscores(xs: &[f64]) -> Vec<f64> {
     xs.iter().map(|&x| (x - x_median) / mad).collect()
 }
 
+pub fn modified_zscores<Q: UnsafeRawValue>(values: &[Q]) -> Vec<f64> {
+    let values: Vec<_> = values.iter().map(|q| q.unsafe_raw_value()).collect();
+    modified_zscores_f64(&values)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;