I am calling fundamental data in research, and some companies have the same data year after year. I have included 3 companies for which I have noticed this below. FB was included as a reference.
  qb = QuantBook()
symbols = ['ZMH', 'XRAY', 'AAS', 'FB']
for s in symbols:
qb.AddEquity(s)


start_time = datetime(2020, 1, 2)
end_time = datetime(2020, 1, 2)

ig_2019 = qb.GetFundamental(symbols, "OperationRatios.NetIncomeGrowth.OneYear", start_time, end_time)

start_time = datetime(2019, 1, 2)
end_time = datetime(2019, 1, 2)

ig_2018 = qb.GetFundamental(symbols, "OperationRatios.NetIncomeGrowth.OneYear", start_time, end_time)

start_time = datetime(2018, 1, 2)
end_time = datetime(2018, 1, 2)

ig_2017 = qb.GetFundamental(symbols, "OperationRatios.NetIncomeGrowth.OneYear", start_time, end_time)

start_time = datetime(2017, 1, 3)
end_time = datetime(2017, 1, 3)

ig_2016 = qb.GetFundamental(symbols, "OperationRatios.NetIncomeGrowth.OneYear", start_time, end_time)

start_time = datetime(2016, 1, 4)
end_time = datetime(2016, 1, 4)

ig_2015 = qb.GetFundamental(symbols, "OperationRatios.NetIncomeGrowth.OneYear", start_time, end_time)

start_time = datetime(2015, 1, 2)
end_time = datetime(2015, 1, 2)

ig_2014 = qb.GetFundamental(symbols, "OperationRatios.NetIncomeGrowth.OneYear", start_time, end_time)

all_ig = pd.concat([ig_2019, ig_2018, ig_2017, ig_2016, ig_2015, ig_2014], axis=0)

all_ig

 


AAS R735QTJ8XC9X FB V6OIPNZEM8V9 XRAY R735QTJ8XC9X ZMH S6ZZPKTVDY05
2020-01-02 0.466874 -0.164029 0.711385 -0.053745
2019-01-02 0.466874 0.387724 0.711385 -0.053745
2018-01-02 0.466874 0.559558 0.711385 -0.053745
2017-01-03 0.466874 1.770336 0.711385 -0.053745
2016-01-04 0.466874 0.254422 -0.221939 -0.053745
2015-01-02 0.466874 0.960000 0.030850 -0.053745