Taxes have become one of the linchpin issues of the 2016 presidential election, with the two candidates taking wildly different views of what companies should pay.

So how much do large companies actually pay in taxes and who is paying the least?

WalletHub set out to answer that question and broke down the overall tax rate for the S&P 100 in 2015 using the companies' annual reports.

As opposed to the supposed 35% federal statutory corporate tax rate in the US, these companies paid an average rate around 28% for the year, including federal, state, and international taxes.

We've compiled a list of the 18 firms that WalletHub found which reported positive income and paid less than a 20% overall tax rate in 2015.

There is a wide variety of firms, but a few themes jump out. For one, a lot of pharmaceutical companies are getting tax breaks--6 of the 18 companies in the list are related to pharmaceuticals or biotech. Additionally, tech firms did well too, with names such as PayPal and Qualcomm making the lowest 18.

Walgreens Boots Alliance

Ticker: WBA

Overall Tax Rate: 19.9%

State Tax Rate: 30.2%

Federal Tax Rate: 3.9%

International Tax Rate: N/A

Cisco

Ticker: CSCO

Overall Tax Rate: 19.8%

State Tax Rate: 45.5%

Federal Tax Rate: 3.1%

International Tax Rate: 6.3%

Johnson & Johnson

Ticker: JNJ

Overall Tax Rate: 19.7%

State Tax Rate: N/A

Federal Tax Rate: N/A

International Tax Rate: 9.1%

Intel

Ticker: INTC

Overall Tax Rate: 19.6%

State Tax Rate: 22.3%

Federal Tax Rate: N/A

International Tax Rate: N/A

Qualcom

Ticker: QCOM

Overall Tax Rate: 18.8%

State Tax Rate: -2.5%

Federal Tax Rate: 0.2%

International Tax Rate: 36.9%

Bank of New York Mellon

Ticker: PCLN

Overall Tax Rate: 18.4%

State Tax Rate: 55.2%

Federal Tax Rate: 138.9%

International Tax Rate: 16.4%

Abbott Laboratories

Ticker: ABT

Overall Tax Rate: 18.1%

State Tax Rate: N/A

Federal Tax Rate: N/A

International Tax Rate: 8.4%

PayPal

Ticker: PYPL

Overall Tax Rate: 17.5%

State Tax Rate: Negative income

Federal Tax Rate: Negative income

International Tax Rate: N/A

Merck and Co.

Ticker: MRK

Overall Tax Rate: 17.4%

State Tax Rate: 8.0%

Federal Tax Rate: 3.6%

International Tax Rate: 21.6%

Alphabet

Overall Tax Rate: 16.8%

State Tax Rate: 36.7%

Federal Tax Rate: -5.3%

International Tax Rate: 6.2%

Gilead Sciences

Ticker: GILD

Overall Tax Rate: 16.4%

State Tax Rate: 40.9%

Federal Tax Rate: 1.7%

International Tax Rate: 1.2%

IBM

Ticker: IBM

Overall Tax Rate: 16.2%

State Tax Rate: 3.9%

Federal Tax Rate: 4.1%

International Tax Rate: 21.0%

Eli Lilly

Ticker: LLY

Overall Tax Rate: 13.7%

State Tax Rate: -3.0%

Federal Tax Rate: 5.6%

International Tax Rate: 19.6%

Amgen

Ticker: AMGN

Overall Tax Rate: 13.0%%

State Tax Rate: 21.6%

Federal Tax Rate: -1.0%

International Tax Rate: 5.8%

Twenty-First Century Fox

Ticker: FOXA

Overall Tax Rate: 12.6%%

State Tax Rate: N/A

Federal Tax Rate: N/A

International Tax Rate: Negative income

Mondelez International

Ticker: MDLZ

Overall Tax Rate: 7.5%

State Tax Rate: 107.0%

Federal Tax Rate: 7.0%

International Tax Rate: 6.9%

Chevron

Ticker: CVX

Overall Tax Rate: 2.7%

State Tax Rate: Negative income

Federal Tax Rate: Negative income

International Tax Rate: 23.6%

General Motors

Ticker: GM

Overall Tax Rate: -34.3%

State Tax Rate: 18.0%

Federal Tax Rate: 3.5%

International Tax Rate: Negative income