4406 Railway or tramway sleepers `cross-ties` of wood

4406 (01/1988-..) Railway or tramway sleepers `cross-ties` of wood 44061000 (01/1988-12/2016) Railway or tramway sleepers `cross-ties` of wood, not impregnated 44061100 (01/2017-..) Railway or tramway sleepers `cross-ties` of wood, not impregnated, coniferous 44061200 (01/2017-..) Railway or tramway sleepers `cross-ties` of wood, not impregnated, non-coniferous 44069000 (01/1988-12/2016) Railway or tramway sleepers `cross-ties` of wood, impregnated 44069100 (01/2017-..) Railway or tramway sleepers `cross-ties` of wood, impregnated, coniferous 44069200 (01/2017-..) Railway or tramway sleepers `cross-ties` of wood, impregnated, non-coniferous