Brihat Parashara Hora Shastra
तदूर्ध्वं स्वल्पफलदं दशोर्ध्वं मध्यमं स्मृतम्। तिय्यूर्धं पूर्णफलदं बोध्यं सर्वं खचारिणाम्॥ २७॥
If it is above 5, but below 10, the Grah will yield some good effects. Later on up to 15 it is indicative of mediocre effect. A Grah with above 15 will yield wholly favourable effects.
english translation
tadUrdhvaM svalpaphaladaM dazordhvaM madhyamaM smRtam। tiyyUrdhaM pUrNaphaladaM bodhyaM sarvaM khacAriNAm॥ 27॥
hk transliteration by Sanscript