Table:
text: The Dillards
Singles
Singles
Year_ Title Billboard_Hot_100 Album Label
1963 Dooley — Back Porch Bluegrass Elektra
1963 Hootin` Banjo [Duelin` Banjo] — Back Porch Bluegrass Elektra
1965 Nobody Knows — singles only Capitol
1966 The Last Thing On My Mind — singles only Capitol
1968 Reason To Believe — Wheatstraw Suite Elektra
1969 Listen To The Sound — Wheatstraw Suite Elektra
1970 Rainmaker — Copperfields Elektra
1970 Close The Door Lightly — Copperfields Elektra
1970 One Too Many Mornings — singles only White Whale
1970 Comin` Home Again — singles only White Whale
1971 It`s About Time No.92 singles only Anthem
1972 One A.M. No.111 Roots and Branches Anthem

Question: What are the total root and branch years for The Dillards?