Penguins:
2017-18: 6
2016-17: 6
2015-16: 7
2014-15: 6
2013-14: 4
2012-13: 11
2011-12: 4
2010-11: 2
2009-10: 7
2008-09: 12
2007-08: 4
2006-07: 8 (five trades made on 2/27/07)
2005-06: 9
2004-05: no trades (lockout)
2003-04: 9
2002-03: 11 (another day with five trades, this time on 3/11/03. This was my bet for the most active year.)
2001-02: 8
2000-01: 11
1999-00: 8
1998-99: 4
1997-98: 6
1996-97: 9
1995-96: 10
1994-95: 5
1993-94: 5
1992-93: 4
1991-92: 4
1990-91: 8
1989-90: 7
1988-89: 8
1987-88: 3
1986-87: 7
1985-86: 7
1984-85: 5
1983-84: 10 (also one additional trade that was voided [Glen Mulvey to PIT for futures])
1982-83: 3
1981-82: 6
1980-81: 6
1979-80: 3
1978-79: 7
1977-78: 15 (Penguins sold their 7th, 9th, 10th, 11th, 12th, 13th, and 14th round draft picks in separate transactions for cash)
1976-77: 3
1975-76: 4
1974-75: 6
1973-74: 9
1972-73: 6
1971-72: 6
1970-71: 5
1969-70: 4
1968-69: 12
1967-68: 5
(All seasons are defined as from July 1 to June 30)
Most transactions: 1977-78 (15) or 1968-69 (12), depending on whether you want to count selling picks for cash.
Least amount of transactions: 2010-11 (2): Penguins acquire Kovalev from Senators for a conditional 7th (pick 203 in the 2011 draft, Sens select Ryan Dzingel); Penguins acquire Neal/Niskanen for Goligoski.