why was the cash flow from Operating Activities less than Net Income in 2018, but more than Net Income in 2019? The answer should be supported by empirical analysis (i.e. hard numbers)

\begin{tabular}{|c|c|c|c|} \hline A & B & c & 0 \\ \hline \multirow{2}{*}{ Consolidated Statement of Cash Flaws - uSD (\$) $ in Millions } & \multicolumn{3}{|c|}{12 Months Ended } \\ \hline & Dex. 28, 2019 & Dec. 29,2018 & Dec. 30,2017 \\ \hline \multicolumn{4}{|l|}{ Operating Activities } \\ \hline Net income & $7,353 & $12,559 & $4,908 \\ \hline Depreciation and amortization & 2,432 & 2,399 & 2,369 \\ \hline Share-based compensation expense & 237 & 256 & 292 \\ \hline Restructuring and impairment charges & 370 & 308 & 295 \\ \hline Cash payments for restructuring charges & (350) & {[255]} & (113) \\ \hline Pension and retiree medical plan expenses & 519 & 221 & 221 \\ \hline Pension and retiree medical plan contributions. & (716) & (1,708) & (220) \\ \hline Deferred income taxes and other tax charges and credits & 453 & [531] & 619 \\ \hline Oaher net tax benefits related to international reorganizations & (2) & (4,347) & 0 \\ \hline Net tax (benefit)/expense related to the TCI Act & (8) & (28) & 2,451 \\ \hline Tax payments related to the TCI Act & (423) & [115] & 0 \\ \hline \multicolumn{4}{|l|}{ Change in assets and liabilities [Abstract] } \\ \hline Accounts and notes recelvable & (650) & {[253]} & (202) \\ \hline Inventories & (190) & {[174]} & [168] \\ \hline Prepaid expenses and other current assets & (87) & 9 & 20 \\ \hline Accounts payable and other current liabilities & 735 & 382 & 201 \\ \hline Income taxes payable & (287) & 448 & [338] \\ \hline Othes, net & 263 & [256) & (305) \\ \hline Net Cash Provided by (Used in) Operating Activities & 9,649 & 9,415 & 10,030 \\ \hline \multicolumn{4}{|l|}{ Investing Activities } \\ \hline Capital spending & (4,232) & (3,282) & (2,969) \\ \hline Sales of property, plant and equlpment & 170 & 134 & 180 \\ \hline Acquisition of Sodastream, net of cash and cash equivalents acquired & (1,939) & (1,197) & 0 \\ \hline Other acquisitions and investments in noncontrolled affiliates & (778) & {[299]} & (61) \\ \hline Divestitures & 253 & sos & 267 \\ \hline \multicolumn{4}{|l|}{ Short-term investments, by oripinal maturity: } \\ \hline More than three months - purchases & 0 & (5,637) & (18,385) \\ \hline More than three months - maturities & 16 & 12,824 & 15,744 \\ \hline More than three months - sales & 62 & 1,498 & 790 \\ \hline Three months or less, net & 19 & 16 & 2 \\ \hline Other investing net & (8) & 2 & 29 \\ \hline Net Cash (Used for)/Provided by Investing Activities & (6,437) & 4,564 & (4,403) \\ \hline \multicolumn{4}{|l|}{ Financing Activities } \\ \hline Proceeds from issuances of long-term debt & 4,621 & 0 & 7,509 \\ \hline Payments of long-term debt & (3,970) & (4,007) & {[4,406]} \\ \hline Cash tender and exchange offers/debt redemptions & (1,007) & (1,589) & 0 \\ \hline \multicolumn{4}{|l|}{ Short-term borrowings, by original maturity } \\ \hline More than three months - proceeds & 6 & 3 & 91 \\ \hline More than three months - payments & (2) & (17) & (128) \\ \hline Three months or less, net & (3) & (1,352) & (1,016) \\ \hline Cash dlvidends paild & (5,304) & (4,930) & (4,472] \\ \hline Share repurchases - common & (3,000) & (2,000) & (2,000) \\ \hline Share repurchases - preferred & 0 & (2) & (S) \\ \hline Proceeds from exercises of stock options & 329 & 281 & 462 \\ \hline Withholding tax payments on RSUs, PSUs and PEPunits converted & (114) & {[103)} & (145) \\ \hline Othes financine & (45) & (53) & (76) \\ \hline Net Cash Used for Financing Activities & (B,4B9) & (13,769) & (4,186} \\ \hline Effect of exchange rate changes on cash and cash equivalents and restricted cash & 78 & (98) & 47 \\ \hline Cash and Cash Equivalents and Restricted Cash, Period Increase (Decrease) & (5,199) & 112 & 1,488 \\ \hline Cash and cash equivalents and restricted cash & $5,570 & $10,769 & $10,657 \\ \hline \end{tabular}