CEO tenure from Execucomp data

[Ismat Jahan]

I am working with Executive characteristics. Using Execucomp data from 1992 to 2019. I need to generate CEO_Tenure (CEO tenure in years at each financial statement date; which is YEAR here)Please help me.

Sample looks like this;

EXEC_FULLNAME	CO_PER_ROL	GVKEY	EXECID	YEAR	BECAMECEO	JOINED_CO	REJOIN	LEFTOFC	LEFTCO	RELEFT	PCEO	CUSIP	TICKER	SIC
Ira A. Eichner	5622	1004	9248	1992	19550101			19961001	19990531			36110	AIR	5080
David P. Storch	5623	1004	9249	1992	19961009			20180531				36110	AIR	5080
Philip C. Slapke	5624	1004	9250	1992								36110	AIR	5080
Howard A. Pulsifer	5625	1004	9251	1992								36110	AIR	5080
Timothy J. Romenesko	5626	1004	9252	1992								36110	AIR	5080
Ira A. Eichner	5622	1004	9248	1993	19550101			19961001	19990531			36110	AIR	5080
David P. Storch	5623	1004	9249	1993	19961009			20180531				36110	AIR	5080
Philip C. Slapke	5624	1004	9250	1993								36110	AIR	5080
Howard A. Pulsifer	5625	1004	9251	1993								36110	AIR	5080
Timothy J. Romenesko	5626	1004	9252	1993								36110	AIR	5080
William J. Cadogan	2611	1013	6	1992	19911101	19870601		20010215	20011101			88630	ADCT.1	3661
Lynn J. Davis	2612	1013	3879	1992					20011001			88630	ADCT.1	3661
Jeffrey S. Wetherell	2613	1013	3880	1992		19911201						88630	ADCT.1	3661
William B. Porter	2614	1013	3881	1992					19950101			88630	ADCT.1	3661
Lawrence D. Asten	2615	1013	3882	1992		19920201						88630	ADCT.1	3661
William J. Cadogan	2611	1013	6	1993	19911101	19870601		20010215	20011101			88630	ADCT.1	3661
Lynn J. Davis	2612	1013	3879	1993					20011001			88630	ADCT.1	3661
Jeffrey S. Wetherell	2613	1013	3880	1993		19911201						88630	ADCT.1	3661
William B. Porter	2614	1013	3881	1993					19950101			88630	ADCT.1	3661