diff --git a/pyzebra/__init__.py b/pyzebra/__init__.py
index e784895..07faae7 100644
--- a/pyzebra/__init__.py
+++ b/pyzebra/__init__.py
@@ -4,4 +4,8 @@ from pyzebra.h5 import *
 from pyzebra.xtal import *
 from pyzebra.ccl_process import *
 
+ZEBRA_PROPOSALS_PATHS = [
+    f"/afs/psi.ch/project/sinqdata/{year}/zebra/" for year in (2016, 2017, 2018, 2020, 2021)
+]
+
 __version__ = "0.3.2"
diff --git a/pyzebra/app/panel_ccl_integrate.py b/pyzebra/app/panel_ccl_integrate.py
index 63ec5af..2d41511 100644
--- a/pyzebra/app/panel_ccl_integrate.py
+++ b/pyzebra/app/panel_ccl_integrate.py
@@ -76,8 +76,14 @@ def create():
 
     def proposal_textinput_callback(_attr, _old, new):
         proposal = new.strip()
-        year = new[:4]
-        proposal_path = f"/afs/psi.ch/project/sinqdata/{year}/zebra/{proposal}"
+        for zebra_proposals_path in pyzebra.ZEBRA_PROPOSALS_PATHS:
+            proposal_path = os.path.join(zebra_proposals_path, proposal)
+            if os.path.isdir(proposal_path):
+                # found it
+                break
+        else:
+            raise ValueError(f"Can not find data for proposal '{proposal}'.")
+
         file_list = []
         for file in os.listdir(proposal_path):
             if file.endswith((".ccl", ".dat")):
diff --git a/pyzebra/app/panel_hdf_viewer.py b/pyzebra/app/panel_hdf_viewer.py
index 54de421..079d9dd 100644
--- a/pyzebra/app/panel_hdf_viewer.py
+++ b/pyzebra/app/panel_hdf_viewer.py
@@ -55,8 +55,14 @@ def create():
 
     def proposal_textinput_callback(_attr, _old, new):
         proposal = new.strip()
-        year = new[:4]
-        proposal_path = f"/afs/psi.ch/project/sinqdata/{year}/zebra/{proposal}"
+        for zebra_proposals_path in pyzebra.ZEBRA_PROPOSALS_PATHS:
+            proposal_path = os.path.join(zebra_proposals_path, proposal)
+            if os.path.isdir(proposal_path):
+                # found it
+                break
+        else:
+            raise ValueError(f"Can not find data for proposal '{proposal}'.")
+
         file_list = []
         for file in os.listdir(proposal_path):
             if file.endswith(".hdf"):
diff --git a/pyzebra/app/panel_param_study.py b/pyzebra/app/panel_param_study.py
index ea265af..9ad284f 100644
--- a/pyzebra/app/panel_param_study.py
+++ b/pyzebra/app/panel_param_study.py
@@ -81,8 +81,14 @@ def create():
 
     def proposal_textinput_callback(_attr, _old, new):
         proposal = new.strip()
-        year = new[:4]
-        proposal_path = f"/afs/psi.ch/project/sinqdata/{year}/zebra/{proposal}"
+        for zebra_proposals_path in pyzebra.ZEBRA_PROPOSALS_PATHS:
+            proposal_path = os.path.join(zebra_proposals_path, proposal)
+            if os.path.isdir(proposal_path):
+                # found it
+                break
+        else:
+            raise ValueError(f"Can not find data for proposal '{proposal}'.")
+
         file_list = []
         for file in os.listdir(proposal_path):
             if file.endswith((".ccl", ".dat")):