diff --git a/sensospot_data/__init__.py b/sensospot_data/__init__.py
index 2a846d3..e4e197c 100644
--- a/sensospot_data/__init__.py
+++ b/sensospot_data/__init__.py
@@ -3,7 +3,7 @@
 Parsing the numerical output from Sensovations Sensospot image analysis.
 """
 
-__version__ = "0.6.0"
+__version__ = "0.6.1"
 
 
 import sys
diff --git a/sensospot_data/columns.py b/sensospot_data/columns.py
index 4b177aa..b36a656 100644
--- a/sensospot_data/columns.py
+++ b/sensospot_data/columns.py
@@ -71,13 +71,35 @@ PARSED_DATA_COLUMN_SET = {
 
 # list of columns to ensure a pandas numeric type
 RAW_DATA_NUMERIC_COLUMNS = {
+    RAW_DATA_POS_ID,
+    RAW_DATA_POS_X,
+    RAW_DATA_POS_Y,
+    RAW_DATA_POS_NOM_X,
+    RAW_DATA_POS_NOM_Y,
     RAW_DATA_BKG_MEAN,
-    RAW_DATA_SPOT_MEAN,
     RAW_DATA_BKG_MEDIAN,
-    RAW_DATA_SPOT_MEDIAN,
     RAW_DATA_BKG_STDDEV,
+    RAW_DATA_BKG_SUM,
+    RAW_DATA_SPOT_MEAN,
+    RAW_DATA_SPOT_MEDIAN,
     RAW_DATA_SPOT_STDDEV,
+    RAW_DATA_SPOT_SUM,
+    RAW_DATA_SPOT_DIAMETER,
+    META_DATA_EXPOSURE_ID,
+    META_DATA_WELL_COLUMN,
+}
+
+
+# set of columns directly dependent on exposure time
+
+EXPOSURE_DEPENDENT_COLUMNS = {
+    RAW_DATA_BKG_MEAN,
+    RAW_DATA_BKG_MEDIAN,
+    RAW_DATA_BKG_STDDEV,
     RAW_DATA_BKG_SUM,
+    RAW_DATA_SPOT_MEAN,
+    RAW_DATA_SPOT_MEDIAN,
+    RAW_DATA_SPOT_STDDEV,
     RAW_DATA_SPOT_SUM,
 }