import pandas as pd

df = pd.read_csv('Data_Tracerstudy/Data_2019_Tracer_study.csv', sep=';', encoding='utf-8-sig')
print("Non-null count per column in 2019 (out of 30 rows):")
for col in df.columns:
    cnt = df[col].notna().sum()
    if cnt < 30:
        print(f"  {col}: {cnt}/30 non-null ({30-cnt} are NaN in CSV)")