1981—Subsec. (b). Pub. L. 97–34 substituted “calendar year” for “calendar quarters”.
1976—Subsec. (c). Pub. L. 94–455 added subsec. (c).
1970—Subsec. (b). Pub. L. 91–614 substituted “calendar quarter” for “calendar year”.
Amendment by Pub. L. 97–34 applicable with respect to gifts made after
Amendment by Pub. L. 91–614 applicable with respect to gifts made after