The letter is Y

Xiangen Xia to Kim Yagle
Kimberly Yagle to R Yancy
W Yancy to Prachube Yannacci
Donna Yannaccone to Marsha Yarnell
R Yarnell to Roger Yates
Ronald Yates to Jimmy Yeako
Max Yealey to V Yelton-Manlove
Don Yelton to Scott Yerkes
Theodore Yerkes to F Yin
C Yinger to A Yoder
Amanda Yoder to Michael Yoder
Nathan Yoder to A Yoor
Seung Yoo to Joseph Yost
Kenneth Yost to Betty Young
Billie Young to Dan Young
Dana Young to K Younger
Brett Youngerman to Jackie Young
James Young to L Young
Larry Young to R Young
Ralph Young to T Young
Ted Young to Sam Youse
Samuel Youse to Mi Yun