diff --git a/examples/10_tracking_diagnostics/pet_normalised_lifetime.py b/examples/10_tracking_diagnostics/pet_normalised_lifetime.py
new file mode 100644
index 00000000..493660cb
--- /dev/null
+++ b/examples/10_tracking_diagnostics/pet_normalised_lifetime.py
@@ -0,0 +1,81 @@
+"""
+Normalised Eddy Lifetimes
+=========================
+
+"""
+
+import py_eddy_tracker_sample
+from matplotlib import pyplot as plt
+from numba import njit, prange
+from numpy import float32, interp, linspace, unique, where, zeros
+
+from py_eddy_tracker.observations.tracking import TrackEddiesObservations
+
+
+@njit(cache=True, parallel=True, fastmath=True)
+def eddy_norm_lifetime(eddy_var, tracks, xvals, unique_tracks, lifetime_max, out):
+    """"""
+    for i in prange(unique_tracks.size):
+        trk1d_i = where(tracks == unique_tracks[i])[0]
+        # out = out + atleast_1d(interp(xvals, linspace(0, 1, trk1d_i.size), eddy_var[trk1d_i]))
+        out += interp(xvals, linspace(0, 1, trk1d_i.size), eddy_var[trk1d_i])
+    return out / len(unique_tracks)
+
+
+if __name__ == "__main__":
+
+    plt.close("all")
+
+    a = TrackEddiesObservations.load_file(
+        py_eddy_tracker_sample.get_path(
+            "eddies_med_adt_allsat_dt2018/Anticyclonic.zarr"
+        )
+    )
+    c = TrackEddiesObservations.load_file(
+        py_eddy_tracker_sample.get_path(
+          "eddies_med_adt_allsat_dt2018/Cyclonic.zarr"
+        )
+    )
+
+    unique_tracks, counts = unique(a.tracks, return_counts=True)
+    lifetime_max = counts.argmax()
+    xvals = linspace(0, 1, lifetime_max)
+    AC_radius = zeros(lifetime_max, dtype=float32)
+    AC_amplitude = zeros(lifetime_max, dtype=float32)
+    CC_radius = zeros(lifetime_max, dtype=float32)
+    CC_amplitude = zeros(lifetime_max, dtype=float32)
+
+    # Radius
+    AC_radius = eddy_norm_lifetime(
+        a.radius_s, a.tracks, xvals, unique_tracks, lifetime_max, AC_radius
+    )
+    # Amplitude
+    AC_amplitude = eddy_norm_lifetime(
+        a.amplitude, a.tracks, xvals, unique_tracks, lifetime_max, AC_amplitude
+    )
+
+    # Radius
+    CC_radius = eddy_norm_lifetime(
+        c.radius_s, c.tracks, xvals, unique_tracks, lifetime_max, CC_radius
+    )
+    # Amplitude
+    CC_amplitude = eddy_norm_lifetime(
+        c.amplitude, c.tracks, xvals, unique_tracks, lifetime_max, CC_amplitude
+    )
+
+    fig, axs = plt.subplots(nrows=2, figsize=(8, 5))
+
+    axs[0].set_title("Normalised Mean Radius")
+    axs[0].plot(xvals, AC_radius)
+    axs[0].plot(xvals, CC_radius)
+    axs[0].set_ylabel("Radius (m)")
+
+    axs[1].set_title("Normalised Mean Amplitude")
+    (AA,) = axs[1].plot(xvals, AC_amplitude, label="AC")
+    (CC,) = axs[1].plot(xvals, CC_amplitude, label="CC")
+    axs[1].set_ylabel("Amplitude (m)")
+
+    axs[1].legend(handles=[AA, CC])
+
+    fig.tight_layout()
+    plt.show()