As far as I can tell, the bonus to Phase (704) for weightlessness has tiers that are actually at 1 pound thresholds, but only the 2 pound thresholds were released / officially tabulated. It seems that one just interpolates between the two-pound thresholds and rounds the requirement up.

Assuming I copied it right we normally have ( https://gswiki.play.net/Phase_(704)#Phasing_For_Weightlessness ):

Ranks	Pounds
0	10
3	12
7	14
12	16
18	18
25	20
33	22
42	24
52	26
63	28
75	30
88	32
102	34
117	36
133	38
150	40
168	42
187	44
207	46
228	48
250	50

I have only tested the point at 82 ranks just now (I think I checked at 69 but am too lazy to check logs). I calculated it should look like the following table if it follows regular rules. This assumes I didn't make too many mistakes in mental math / typos.

Ranks	Pounds
0	10
2	11
3	12
5	13
7	14
10	15
12	16
15	17
18	18
22	19
25	20
29	21
33	22
38	23
42	24
47	25
52	26
58	27
63	28
69	29
75	30
82	31
88	32
95	33
102	34
110	35
117	36
125	37
133	38
142	39
150	40
159	41
168	42
178	43
187	44
197	45
207	46
218	47
228	48
239	49
250	50

NIR want to confirm this and I'll get a corrected version on gswiki...