Try pasting the following into cell B100 and copying down to cell B6907:
Formula: copy to clipboard 
=INDEX(A$3:A$91,AGGREGATE(15,6,(ROW(A$3:A$91)-ROW(A$2))/(B$3:EZ$91<>""),ROWS(A$1:A1)))&RIGHT(TEXT(MOD(AGGREGATE(15,6,ROW(A$3:A$91)*1000+COLUMN(B$1:EZ$1)/(B$3:EZ$91<>""),ROWS(A$1:A1))/1000,1),".000"),3)-1

Let us know if you have any questions.