def calculate_deltas(data_frame):
    """
    Calcualtes the changes in the dataset betwwen

    Parameters
    ----------
    data_frame: Pandas dataframe
        Dataframe with no missing values

    Returns
    -------
    delta_frame: Pandas dataframe
        Dataframe of deltas of time series
    """

    delta_frame = data_frame

    # Calculate deltas
    delta_frame.iloc[:-1, :] = data_frame.iloc[1:, :].to_numpy() \
                             - data_frame.iloc[:-1, :].to_numpy()
    delta_frame = delta_frame.iloc[1:-1, :]

    return delta_frame