diff --git a/trace_agg/tests/data/sample_em_traces.csv b/trace_agg/tests/data/sample_em_traces.csv
new file mode 100644
index 0000000..56a06f0
--- /dev/null
+++ b/trace_agg/tests/data/sample_em_traces.csv
@@ -0,0 +1,7 @@
+timestamp,amplitude,bandpower
+2024-01-01T00:00:00Z,0.12,0.0045
+2024-01-01T00:00:01Z,0.18,0.0050
+2024-01-01T00:00:02Z,0.15,0.0048
+2024-01-01T00:00:03Z,0.10,0.0039
+2024-01-01T00:00:04Z,0.22,0.0053
+2024-01-01T00:00:05Z,0.25,0.0057
\ No newline at end of file