July 27, 2019
July 28, 2018
Increase (Decrease)
Cash and cash equivalents .
$11,750
$8,934
$2,816
Available-for-sale debt investments
21,660
37,009
(15,349)
Marketable equity securities
3
605
(602)
Total
$33,413
$46,548
$(13,135)

text: Balance Sheet and Cash Flows
text: Cash and Cash Equivalents and Investments The following table summarizes our cash and cash equivalents and investments (in millions):
text: The net decrease in cash and cash equivalents and investments from fiscal 2018 to fiscal 2019 was primarily driven by cash returned to shareholders in the form of repurchases of common stock of $20.7 billion under the stock repurchase program and cash dividends of $6.0 billion, net cash paid for acquisitions and divestitures of $2.2 billion, a net decrease in debt of $1.1 billion, and capital expenditures of $0.9 billion. These uses of cash were partially offset by cash provided by operating activities of $15.8 billion and the timing of settlements of investments and other of $2.0 billion.
text: In addition to cash requirements in the normal course of business, on July 9, 2019 we announced our intent to acquire Acacia Communications, Inc. (“Acacia”) for a purchase consideration of approximately $2.6 billion in cash. Additionally, $0.7 billion of the U.S. transition tax on accumulated earnings for foreign subsidiaries, $6.0 billion of long-term debt and $4.2 billion of commercial paper notes outstanding at July 27, 2019, are payable within the next 12 months from the balance sheet date. See further discussion of liquidity and future payments under “Contractual Obligations” and “Liquidity and Capital Resource Requirements” below.
text: We maintain an investment portfolio of various holdings, types, and maturities. We classify our investments as short-term investments based on their nature and their availability for use in current operations. We believe the overall credit quality of our portfolio is strong, with our cash equivalents and our available-for-sale debt investment portfolio consisting primarily of high quality investment-grade securities. We believe that our strong cash and cash equivalents and investments position allows us to use our cash resources for strategic investments to gain access to new technologies, for acquisitions, for customer financing activities, for working capital needs, and for the repurchase of shares of common stock and payment of dividends as discussed below.

Questions:
question: Which years does the table provide information for  cash and cash equivalents and investments?
answer: 2019
2018
question: How are the company's investments classified as short-term?
answer: based on their nature and their availability for use in current operations.
question: What was the increase (decrease) in available-for-sale debt investments?
answer: (15,349)
scale: million
question: What was the difference between cash and cash equivalents and Available-for-sale debt investments in 2019?
answer: 9910
derivation: 21,660-11,750
scale: million
question: How many years did Marketable equity securities exceed $500 million? 
answer: 1
derivation: 2018
question: What was the percentage change in the total between 2018 and 2019?
answer: -28.22
derivation: (33,413-46,548)/46,548
scale: percent