New Delhi: Forbes has released its annual list of the world's richest billionaires, showing 172 women on the list, which is a striking 25 per cent increase from the last year. But despite their record-breaking presence, women still only make up 10 per cent of the billionaires club. Among the billion-dollar ladies are Sheryl Sandberg, Lean In scribe and COO of Facebook; Meg Whitman, president of Hewlett-Packard; and Christy Walton, whose late husband was the son of Walmart founder Sam Walton.Sandberg is also amongst the world's youngest self-made billionaires and joins Whitman as a female tech billionaire. Other women to join the list with a self-made fortune include Folorunsho Alakija, who is Nigeria's first female billionaire with her lucrative oil-producing company earning her a fortune of $2.5 billion, and the co-CEO of online gambling site Bet365, Denise Coates.Reports suggest that only 32 of the 172 female billionaires actually struck it rich on their own; others inherited wealth from their parents or husbands. Here is the list: Margarita Louis-DreyfusNet worth: $8.1 billionAntonia JohnsonNet worth: $8.5 billionElaine MarshallNet worth: $8.8 billionCharlene de Carvalho-HeinekenNet worth: $10.4 billionMiuccia PradaNet worth: $11.1 billionJohanna QuandtNet worth: $12.8 billionLaurene Powell JobsNet worth: $14 billionAnne Cox ChambersNet worth: $15.5 billionAbigail JohnsonNet worth: $17.3 billionSusanne KlattenNet worth: $17.4 billionGina RinehartNet worth: $17.7 billionJacqueline Badger MarsNet worth: $20 billionAlice WaltonNet worth: $34.3 billionLiliane BettencourtNet worth: $34.5 billionChristy WaltonNet worth: $36.7 billion