I would like to display two fixed effects at the end of each column: "FE(i): yes" and "FE(y): yes". I believe I use -esttab- and -estadd- properly, but the outcome just shows "FE(i): yes:" properly. Instead of "FE(y): yes", which I expect to show, "FE(y): " is displayed. Can anybody have a suggestion?

Code:
eststo clear
use http://www.stata-press.com/data/r13/nlswork
xtset idcode year
eststo: xtreg ttl_exp age ind_code occ_code i.year ,fe robust
estadd local fe_i "yes"
estadd local fe_y "yes"
esttab ,  s(N fe_i fe_y, label("N" "FE(i)" "FE(y)" )) ar2 se noconstant star(* .10 ** .05 *** .01) drop(*year)


----------------------------
(1)
ttl_exp
----------------------------
age -0.00861
(0.0618)

ind_code -0.0427***
(0.00897)

occ_code -0.0330***
(0.00806)

_cons 1.171
(1.187)
----------------------------
N 28081
FE(i) yes
FE(y)
----------------------------
Standard errors in parentheses
* p<.10, ** p<.05, *** p<.01