Counting occurrences of sickness in a roster across a year

After re-check it's seem that my solition not working for a long period sick. >_<"

Sorry.

Except in crease of subsitute as

E6

=LEN(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(F6&G6&H6&I6&J6&K6&L6&M6&N6&O6&P6&Q6&R6&S6&T6&U6&V6&W6&X6&Y6&Z6&AA6&AB6,"OFF",""),"SICK","#"),"#####","#"),"####","#"),"###","#"),"##","#"))-
LEN(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(F6&G6&H6&I6&J6&K6&L6&M6&N6&O6&P6&Q6&R6&S6&T6&U6&V6&W6&X6&Y6&Z6&AA6&AB6,"OFF",""),"SICK","#"),"#####","#"),"####","#"),"###","#"),"##","#"),"#",""))

Regards.