The Montreal Canadiens averaged a power-play percentage of 31.9 in 1977-78.

which team has the highest single season power-play percentage by a team

TEAM	PP%	SEASON	GP	W	L	T	PTS	PTS%	G	GA	PK%	S/GP	SA/GP
Montreal Canadiens	31.9	1977-78	80	59	10	11	129	.806	359	183	81.0	32.76	25.94
Toronto Maple Leafs	21.3	1977-78	80	41	29	10	92	.575	271	237	81.4	29.68	30.38
Boston Bruins	20.2	1977-78	80	51	18	11	113	.706	333	218	82.1	30.31	22.49
New York Rangers	28.8	1977-78	80	30	37	13	73	.456	279	280	80.2	28.14	31.38
Chicago Black Hawks	21.0	1977-78	80	32	29	19	83	.519	230	220	84.4	29.21	30.85
Detroit Red Wings	20.8	1977-78	80	32	34	14	78	.488	252	266	78.1	28.41	28.39
Cleveland Barons	15.1	1977-78	80	22	45	13	57	.356	230	325	74.2	26.74	32.80
Los Angeles Kings	19.5	1977-78	80	31	34	15	77	.481	243	245	80.0	31.46	26.89
Minnesota North Stars	14.9	1977-78	80	18	53	9	45	.281	218	325	71.6	28.81	31.50
Philadelphia Flyers	23.6	1977-78	80	45	20	15	105	.656	296	200	80.6	32.94	25.50
Pittsburgh Penguins	21.1	1977-78	80	25	37	18	68	.425	254	321	74.7	28.83	34.86
St. Louis Blues	16.7	1977-78	80	20	47	13	53	.331	195	304	73.3	27.84	29.75
Buffalo Sabres	22.2	1977-78	80	44	19	17	105	.656	288	215	85.8	30.99	27.86
Vancouver Canucks	22.5	1977-78	80	20	43	17	57	.356	239	320	71.5	25.65	30.78
Atlanta Flames	22.5	1977-78	80	34	27	19	87	.544	274	252	80.2	29.23	26.66
New York Islanders	31.4	1977-78	80	48	17	15	111	.694	334	210	83.5	31.13	28.20
Colorado Rockies	22.6	1977-78	80	19	40	21	59	.369	257	305	77.6	30.04	31.64
Washington Capitals	12.5	1977-78	80	17	49	14	48	.300	195	321	71.4	24.95	31.25
Montreal Canadiens	28.3	1978-79	80	52	17	11	115	.719	337	204	83.6	32.16	25.41
Toronto Maple Leafs	25.4	1978-79	80	34	33	13	81	.506	267	252	78.8	30.54	31.48
Boston Bruins	23.6	1978-79	80	43	23	14	100	.625	316	270	74.6	28.06	24.78
New York Rangers	23.9	1978-79	80	40	29	11	91	.569	316	292	74.7	30.89	27.75
Chicago Black Hawks	16.6	1978-79	80	29	36	15	73	.456	244	277	76.4	28.09	34.19
Detroit Red Wings	23.9	1978-79	80	23	41	16	62	.388	252	295	77.4	28.39	28.33
Los Angeles Kings	24.4	1978-79	80	34	34	12	80	.500	292	286	77.6	30.25	29.44