It doesn't sound like much: 5% of the global personal-computer market.

But that number has been a long time coming for Apple (AAPL). The company finally passed 5% of the world PC market in the third quarter, analysts say. It hasn't hit that mark for 15 years.

For years, Apple's worldwide market share was stuck at a measly 2% to 3%, according to this chart from AppleInsider. But with 5.2% in the third quarter, the momentum has been growing strong -- in no small part to Apple's newfound toehold in the workplace.

Check out these figures from a report by Charlie Wolf of Needham & Co.:

• Apple's Mac shipment growth was 24.6% in the third quarter, compared with 5.3% for the overall PC market.

• For the home market, Apple's growth was 25.6% compared with 4% for PCs overall.

• For the business market, shipments saw a whopping 43.8% rise compared with 4.8% for PCs overall.

What's interesting is the one area where the Mac did really badly: education. Apple's shipment growth in that sector saw just 2.9% growth compared to 16.9% for PCs. But Wolf thinks that's because the iPad is eating into Apple's traditional Mac sales for education, AppleInsider reports.

Apple has said that iPad sales were stronger than Mac sales in June in the elementary through high-school education market.

But the real piece of this puzzle that everyone's paying attention to is the lucrative business market. That sector has long been dominated by the Hewlett-Packards (HPQ) and Dells (DELL) of the world, and it seemed like there was little room left for Apple.

But the iPhone and the iPad really paved the way for the Mac to pick up share. Just last month, in fact, Forrester issued a report strongly urging large corporations to let their employees use Macs at work, GigaOm reports.

So many employees were trying to sneak their own Macs into the corporate workplace that Forrester said it's better for companies to recognize and embrace the shift. "Companies Forrester spoke with for this document described a gray market emerging internally, where employees share tips and strategies to use their Macs at work and bypass corporate roadblocks," the report said.

Can Apple maintain this workplace momentum? Will we see the company claim 6% or even 7% of the worldwide market next year? It's looking that way.