def calc_roi(scenario, financial_annual_overview, years):
    """Return on Investment Time Series Function

    Args:
       scenario (object): The farm scenario
       financial_annual_overview (dataframe): The corresponding financial dataframe
       years (int): No. of years the analysis will analyse

    Returns:
        roi (list): Return on investment time series for the no. of years
    """

    roi = []

    for y in range(years+1):
        #if y >= 2:
            roi.append((financial_annual_overview.iloc[30,y] / scenario.capex_full)*100)
        #elif y < 2:
        #   roi.append((financial_annual_overview.iloc[30,y] / scenario.capex_pilot)*100)

    return roi