As a suffix, 率 turns nouns and verbs into quantifiable rates: 成功率 (success rate), 就业率 (employment rate), 出生率 (birth rate), 利率 (interest rate), 增长率 (growth rate). Anywhere a percentage or ratio is named in Chinese, lǜ is doing the work.
mistakes
率 has two readings: lǜ (rate, ratio) and shuài (to lead, frank, rash). The suffix sense - X+率 'the rate of X' - is always lǜ. The verb sense in 率领 and 率先 is shuài. If you see 率 at the END of a compound, it's almost always lǜ; at the START, it's usually shuài.
A horizontal lid stroke capping the silk-twist scene below. Purely positional, the same lid found in 京 and 高, used here as a graphic anchor rather than a meaning-bearing component.
Coiled-silk graph with four flanking marks for drips of water or twisting fingers. Standalone 幺 is 3 strokes; here it carries 7 because the surrounding dots have fused into the same visual unit. This rope-being-twisted core is what 率 originally drew, giving the cluster of senses 'rope, lead, command, rate.'
Bottom cross-piece - the lower frame or weight of the rope-twisting apparatus, not the numeral 'ten' here. With the lid above and the silk between, the whole graph reads as a rope-making scene.
Filed under radical 玄 (xuán, #95) by convention. 玄 is not a separate component in 率, so no strokes are highlighted.
