The Combined Ratings Table below, results from the consideration of the efficiency of the individual as affected first by the most disabling condition, then by the less disabling condition, then by other less disabling conditions, if any, in the order of severity. Thus, a person having a 60 percent disability is considered 40 percent efficient. Proceeding from this 40 percent efficiency, the effect of a further 30 percent disability is to leave only 70 percent of the efficiency remaining after consideration of the first disability, or 28 percent efficiency altogether. The individual is thus 72 percent disabled.                       (a) To use the table, the disabilities will first be arranged in the exact order of their severity, beginning with the greatest disability and then combined with use of table I as hereinafter indicated. For example, if there are two disabilities, the degree of one disability will be read in the left column and the degree of the other in the top row, whichever is appropriate. The figures appearing in the space where the column and row intersect will represent the combined value of the two. This combined value will then be converted to the nearest number divisible by 10, and combined values ending in 5 will be adjusted upward. Thus, with a 50 percent disability and a 30 percent disability, the combined value will be found to be 65 percent, but the 65 percent must be converted to 70 percent to represent the final degree of disability. Similarly, with a disability of 40 percent, and another disability of 20 percent, the combined value is found to be 52 percent, but the 52 percent must be converted to the nearest degree divisible by 10, which is 50 percent. If there are more than two disabilities, the disabilities will also be arranged in the exact order of their severity and the combined value for the first two will be found as previously described for two disabilities. The combined value, exactly as found in table I, will be combined with the degree of the third disability (in order of severity). The combined value for the three disabilities will be found in the space where the column and row intersect, and if there are only three disabilities will be converted to the nearest degree divisible by 10, adjusting final 5's upward. Thus, if there are three disabilities ratable at 60 percent, 40 percent, and 20 percent, respectively, the combined value for the first two will be found opposite 60 and under 40 and is 76 percent. This 76 will be combined with 20 and the combined value for the three is 81 percent. This combined value will be converted to the nearest degree divisible by 10 which is 80 percent. The same procedure will be employed when there are four or more disabilities. (See table I). (b) Except as otherwise provided in this schedule, the disabilities arising from a single disease entity, e.g., diabetes, multiple sclerosis, PTSD, etc., are to be rated separately as are all other disabiling conditions, if any. All disabilities are then to be combined as described in paragraph (a) of this section. The conversion to the nearest degree divisible by 10 will be done only once per rating decision, will follow the combining of all disabilities, and will be the last procedure in determining the combined degree of disability.