Year Ended December 31,

2020

2019

2018

(in thousands)

Interest expense related to debt, including commitment fees

$

—

$

—

$

(257)

Deferred finance cost amortization

—

—

(191)

Interest income

155

733

270

Other interest expense not related to debt

—

—

33

Interest income (expense), net

$

155

$

733

$

(145)

Average effective interest rate, excluding commitment fees

N/A

N/A

7.09%