(1) | Registration Statement (Form S-3 No. 333-216591), |
(2) | Registration Statements (Form S-8 No. 333-143355, Form S-8 No. 333-188796 and Form S-8 No. 333-211328) pertaining to the Company’s 2006 Stock Incentive Plan, |
(3) | Registration Statements (Form S-8 No. 333-182979 and Form S-8 No. 333-218177) pertaining to the Company’s Employee Stock Purchase Plan, and |
(4) | Registration Statement (Form S-8 No. 333-214460) pertaining to the Company’s 2016 Omnibus Incentive Plan; |
/s/ Ernst & Young LLP | |
Denver, Colorado | |
February 21, 2019 |