how many times has a player shot 0 free throws in over 20 minutes

Isaac Walthour didn't have any free-throw attempts when making exactly 0 free throws and playing >20 minutes.

	NAME	FTA	GP	FTM	MIN	MPG	PPG	RPG	APG	SPG	BPG	FGM	FGA	FG%	3PM	3PA	3P%	FT%	TS%	OREB	DREB	TPG	PTS	REB	AST	STL	BLK	TOV	PF	+/-
1	Isaac Walthour I. Walthour	0	4	0	30	7.5	0.5	0.3	0.5			0.3	1.5	16.7					16.7				2	1	2				6
2	Tom Brennan T. Brennan	0	11	0	52	4.7	0.9	0.5	0.2			0.5	1.0	45.5					45.5				10	5	2				5
3	Herm Hedderick H. Hedderick	1	5	0	23	4.6	0.8	0.8	0.4			0.4	1.8	22.2				0.0	21.2				4	4	2				3
4	Doug Bolstorff D. Bolstorff	0	3	0	21	7.0	1.3	0.0	0.0			0.7	1.7	40.0					40.0				4	0	0				1
5	Dave Fedor D. Fedor	1	7	0	27	3.9	0.9	0.9	0.1			0.4	1.4	30.0				0.0	28.7				6	6	1				4
6	Ralph Wells R. Wells	7	3	0	48	16.0	0.7	2.0	2.3			0.3	2.3	14.3				0.0	9.9				2	6	7				6
7	Justus Thigpen J. Thigpen	0	19	0	101	5.3	2.5	0.5	0.4	0.0	0.0	1.3	3.2	40.0					40.0	1.0	0.0		48	10	8	0	0		18
8	Phil Bond P. Bond	0	7	0	21	3.0	0.6	0.6	0.3	0.1	0.0	0.3	0.9	33.3					33.3	0.1	0.4	0.3	4	4	2	1	0	2	1
9	Larry Johnson L. Johnson	2	4	0	38	9.5	1.5	1.3	1.8	1.3	0.5	0.8	3.3	23.1				0.0	21.6	0.3	1.0	0.8	6	5	7	5	2	3	3
10	Dennis Boyd D. Boyd	0	5	0	40	8.0	1.2	0.4	1.4	0.0	0.0	0.6	2.4	25.0					25.0	0.0	0.4	1.2	6	2	7	0	0	6	5
11	Dick Miller D. Miller	0	8	0	53	6.6	1.0	0.9	0.6	0.5	0.0	0.5	1.1	44.4	0.0	0.1	0.0		44.4	0.3	0.6	1.0	8	7	5	4	0	8	5
12	Tony Price T. Price	0	5	0	29	5.8	0.8	0.0	0.6	0.4	0.2	0.4	1.4	28.6	0.0	0.0			28.6	0.0	0.0	0.4	4	0	3	2	1	2	3
13	Steve Lingenfelter S. Lingenfelter	6	10	0	67	6.7	1.0	1.6	0.5	0.1	0.3	0.5	0.7	71.4	0.0	0.0		0.0	51.9	0.4	1.2	0.6	10	16	5	1	3	6	22
14	Jim Zoet J. Zoet	0	7	0	30	4.3	0.3	1.1	0.1	0.1	0.4	0.1	0.7	20.0	0.0	0.0			20.0	0.4	0.7	0.6	2	8	1	1	3	4	9
15	Ken Austin K. Austin	0	7	0	28	4.0	1.7	0.4	0.1	0.1	0.1	0.9	1.9	46.2	0.0	0.0			46.2	0.3	0.1	0.4	12	3	1	1	1	3	7
16	Brian Martin B. Martin	2	8	0	21	2.6	0.8	0.5	0.0	0.0	0.1	0.4	0.9	42.9	0.0	0.0		0.0	38.1	0.1	0.4	0.3	6	4	0	0	1	2	7
17	Bruce Douglas B. Douglas	4	8	0	98	12.3	1.8	1.8	2.1	1.1	0.0	0.9	3.0	29.2	0.0	0.1	0.0	0.0	27.2	0.6	1.1	1.1	14	14	17	9	0	9	9
18	Phil Zevenbergen P. Zevenbergen	2	8	0	58	7.3	3.8	1.6	0.4	0.4	0.1	1.9	3.4	55.6	0.0	0.0		0.0	53.8	0.5	1.1	0.5	30	13	3	3	1	4	12
19	Raymond Brown R. Brown	2	16	0	56	3.5	1.0	0.9	0.3	0.0	0.0	0.5	1.8	28.6	0.0	0.0		0.0	27.7	0.6	0.3	0.4	16	15	4	0	0	6	11
20	Myron Brown M. Brown	0	4	0	23	5.8	2.3	0.8	1.5	0.3	0.0	1.0	1.5	66.7	0.3	0.8	33.3		75.0	0.0	0.8	1.0	9	3	6	1	0	4	2
21	Matt Othick M. Othick	2	4	0	39	9.8	2.0	0.5	1.8	0.3	0.0	0.8	1.3	60.0	0.5	1.0	50.0	0.0	68.0	0.3	0.3	1.0	8	2	7	1	0	4	7
22	Rastko Cvetkovic R. Cvetkovic	4	14	0	48	3.4	0.7	0.8	0.2	0.1	0.1	0.4	1.1	31.3	0.0	0.1	0.0	0.0	28.2	0.3	0.5	0.2	10	11	3	2	1	3	11
23	Cuonzo Martin C. Martin	2	7	0	32	4.6	1.3	0.4	0.4	0.1	0.0	0.4	1.7	25.0	0.4	0.7	60.0	0.0	34.9	0.3	0.1	0.3	9	3	3	1	0	2	2	-2
24	Jeff Webster J. Webster	0	11	0	58	5.3	1.6	0.6	0.3	0.4	0.0	0.7	2.1	34.8	0.2	0.5	33.3		39.1	0.2	0.5	0.3	18	7	3	4	0	3	7
25	William Cunningham W. Cunningham	2	23	0	201	8.7	0.6	1.7	0.1	0.1	0.5	0.3	1.2	25.9	0.0	0.0		0.0	25.1	0.7	0.9	0.2	14	38	2	3	11	5	40	-31