Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
|  |  | Year ended December 31, | Year ended December 31, | Year ended December 31, | Year ended December 31, | Year ended December 31, |
| --- | --- | --- | --- | --- | --- | --- |
|  |  | 2019 | 2018 | 2017 | 2016 | 2015 |
| Financial Data (in millions, except per share amounts): | Operating revenues | $22,428 | $21,965 | $21,146 | $20,289 | $19,820 |
| Financial Data (in millions, except per share amounts): | Operating expenses | 19,471 | 18,759 | 17,739 | 16,767 | 15,821 |
| Financial Data (in millions, except per share amounts): | Operating income | 2,957 | 3,206 | 3,407 | 3,522 | 3,999 |
| Financial Data (in millions, except per share amounts): | Other expenses (income) net | — | 42 | 142 | 72 | 520 |
| Financial Data (in millions, except per share amounts): | Income before taxes | 2,957 | 3,164 | 3,265 | 3,450 | 3,479 |
| Financial Data (in millions, except per share amounts): | Provision (benefit) for income taxes | 657 | 699 | (92) | 1,267 | 1,298 |
| Financial Data (in millions, except per share amounts): | Net income | $2,300 | $2,465 | $3,357 | $2,183 | $2,181 |
| Financial Data (in millions, except per share amounts): | Net income per share, basic | $4.28 | $4.30 | $5.58 | $3.48 | $3.30 |
| Financial Data (in millions, except per share amounts): | Net income per share, diluted | $4.27 | $4.29 | $5.57 | $3.45 | $3.27 |
| Financial Data (in millions, except per share amounts): | Cash dividends per common share | $0.700 | $0.605 | $0.475 | $0.375 | $0.285 |
| Financial Data (in millions, except per share amounts): | Total assets at period-end | $25,895 | $26,243 | $25,110 | $23,286 | $21,312 |
| Financial Data (in millions, except per share amounts): | Long-term obligations at period-end | $1,846 | $2,771 | $3,320 | $2,821 | $2,541 |
| Financial Data (in millions, except per share amounts): | Stockholders’ equity at period-end | $9,832 | $9,853 | $9,641 | $7,784 | $7,358 |
| Operating Data: | Revenue passengers carried (000s) | 134,056 | 134,890 | 130,256 | 124,720 | 118,171 |
| Operating Data: | Enplaned passengers (000s) | 162,681 | 163,606 | 157,677 | 151,740 | 144,575 |
| Operating Data: | Revenue passenger miles (RPMs) (in millions) (a) | 131,345 | 133,322 | 129,041 | 124,798 | 117,500 |
| Operating Data: | Available seat miles (ASMs) (in millions) (b) | 157,254 | 159,795 | 153,811 | 148,522 | 140,501 |
| Operating Data: | Load factor (c) | 83.5% | 83.4% | 83.9% | 84.0% | 83.6% |
| Operating Data: | Average length of passenger haul (miles) | 980 | 988 | 991 | 1,001 | 994 |
| Operating Data: | Average aircraft stage length (miles) | 748 | 757 | 754 | 760 | 750 |
| Operating Data: | Trips flown | 1,367,727 | 1,375,030 | 1,347,893 | 1,311,149 | 1,267,358 |
| Operating Data: | Seats flown (000s) (d) | 206,390 | 207,223 | 200,879 | 193,168 | 184,955 |
| Operating Data: | Seats per trip (e) | 150.9 | 150.7 | 149.0 | 147.3 | 145.9 |
| Operating Data: | Average passenger fare | $154.98 | $151.64 | $151.73 | $152.89 | $154.85 |
| Operating Data: | Passenger revenue yield per RPM (cents) (f) | 15.82 | 15.34 | 15.32 | 15.28 | 15.57 |
| Operating Data: | Operating revenues per ASM (cents) (g)(j) | 14.26 | 13.75 | 13.75 | 13.66 | 13.98 |
| Operating Data: | Passenger revenue per ASM (cents) (h) | 13.21 | 12.80 | 12.85 | 12.84 | 13.02 |
| Operating Data: | Operating expenses per ASM (cents) (i) | 12.38 | 11.74 | 11.53 | 11.29 | 11.26 |
| Operating Data: | Operating expenses per ASM, excluding fuel (cents) | 9.62 | 8.85 | 8.88 | 8.73 | 8.60 |
| Operating Data: | Operating expenses per ASM, excluding fuel and profitsharing (cents) | 9.19 | 8.51 | 8.53 | 8.34 | 8.16 |
| Operating Data: | Fuel costs per gallon, including fuel tax | $2.09 | $2.20 | $1.99 | $1.90 | $1.96 |
| Operating Data: | Fuel costs per gallon, including fuel tax, economic | $2.09 | $2.20 | $2.06 | $2.00 | $2.13 |
| Operating Data: | Fuel consumed, in gallons (millions) | 2,077 | 2,094 | 2,045 | 1,996 | 1,901 |
| Operating Data: | Active fulltime equivalent Employees | 60,767 | 58,803 | 56,110 | 53,536 | 49,583 |
| Operating Data: | Aircraft at end of period | 747 | 750 | 706 | 723 | 704 |
Question:
show me Southwest's Yield Per Passenger Mile in 2018
Answer:
15.34