Anton, The Lord of Hartforth joined the Triple Nine Society in 1985. This is an ultra-high IQ organization for people who score in the top 99.9% of the population. It is 200 times more selective than Mensa.
Lewis Terman developed the original notion of IQ and proposed this scale for classifying IQ scores:

000 - 070: Definite feeble-mindedness
070 - 079: Borderline deficiency
080 - 089: Dullness
090 - 109: Normal or average intelligence
110 - 119: Superior intelligence
115 - 124: Above average (e.g., university students)
125 - 134: Gifted (e.g., post-graduate students)
135 - 144: Highly gifted (e.g., intellectuals)
145 - 154: Genius (e.g., professors)
155 - 164: Genius (e.g., Nobel Prize winners)
165 - 179: High genius
180 - 200: Highest genius
200 -     ? : Immeasurable genius