Year Ended December 31,

2018

2017

2016

(in millions)

Net sales:

Primary Reporting Segment

$

3,884.2

$

3,541.8

$

3,619.6

China

1,007.6

885.9

868.8

Total net sales

$

4,891.8

$

4,427.7

$

4,488.4

Contribution margin(1):

Primary Reporting Segment

$

1,693.5

$

1,534.2

$

1,571.9

China(2)

915.0

790.7

789.3

Total contribution margin

$

2,608.5

$

2,324.9

$

2,361.2

Selling, general, and administrative expenses(2)

1,955.2

1,758.6

1,966.9

Other operating income

(29.8

)

(50.8

)

(63.8

)

Interest expense

181.0

160.8

99.3

Interest income

19.4

14.5

5.9

Other expense (income), net

57.3

(0.4

)

—

Income before income taxes

464.2

471.2

364.7

Income taxes

167.6

257.3

104.7

Net income

$

296.6

$

213.9

$

260.0

Net sales by product line:

Weight Management

$

3,105.8

$

2,842.5

$

2,864.5

Targeted Nutrition

1,243.5

1,082.8

1,062.8

Energy, Sports, and Fitness

308.4

263.8

268.4

Outer Nutrition

91.9

93.9

110.4

Literature, Promotional, and Other(3)

142.2

144.7

182.3

Total net sales

$

4,891.8

$

4,427.7

$

4,488.4

Net sales by geographic area:

United States

$

925.9

$

818.3

$

935.0

China

1,007.6

885.9

868.8

Mexico

467.9

442.7

446.6

Others

2,490.4

2,280.8

2,238.0

Total net sales

$

4,891.8

$

4,427.7

$

4,488.4

(1)

Contribution margin consists of net sales less cost of sales and royalty overrides. For the China segment, contribution margin does not include service fees to China Independent Service Providers.

(2)

Service fees to China Independent Service Providers totaling $523.2 million, $419.5 million, and $407.1 million for the years ended December 31, 2018, 2017, and 2016, respectively, are included in selling, general, and administrative expenses.

(3)

Product buy backs and returns in all product categories are included in the Literature, Promotional, and Other category.