Question: Princess Aisha bint Hussein is the sister of the King who has ruled since what year?

Context paragraphs:
Princess Sara bint Faisal: Princess Sara bint Faisal of Jordan (born 27 March 1997) is the daughter Prince Faisal bin Hussein and Princess Alia, and a niece of King Abdullah II of Jordan.  She is the younger sister of Princess Ayah and Prince Omar, and is also twin to Princess Aisha.  Princess Sara currently attends Amman Baccalaureate School and is a senior.

Princess Iman bint Hussein: Princess Iman bint Hussein (born 24 April 1983) is the daughter of King Hussein and Queen Noor of Jordan.  She has two full brothers, Hamzah and Hashim, and a younger sister, Princess Raiyah.  She is a half-sister to King Abdullah II of Jordan.

Princess Aisha bint Faisal: Princess Aisha bint Faisal of Jordan (born 27 March 1997) is the daughter of Prince Faisal bin Hussein and Princess Alia, and a niece of King Abdullah II of Jordan.  She is the younger sister of Princess Ayah and Prince Omar, and is also twin to Princess Sara.  She attends Amman Baccalaureate School, a private school in Amman, Jordan.

Abdullah II of Jordan: Abdullah II bin Al-Hussein (Arabic: عبد الله الثاني بن الحسين‎ ‎ , "ʿAbdullāh aṯ-ṯānī ibn Al-Ḥusayn", born 30 January 1962) has been King of Jordan since the 1999 death of his father, King Hussein.  According to Abdullah, he is a 41st-generation direct descendant of Muhammad as he belongs to the Hashemite family—who have ruled Jordan since 1921.

Princess Aisha bint Hussein: Princess Aisha bint Hussein (born 23 April 1968) is the sister of King Abdullah II of Jordan and is the twin sister of Princess Zein.  Her parents are Princess Muna al-Hussein and King Hussein.

Princess Zein bint Hussein: Princess Zein bint Hussein (born 23 April 1968) is the sister of King Abdullah II of Jordan and the twin sister of Princess Aisha bint Hussein.

Princess Raiyah bint Hussein: Princess Raiyah bint Hussein (born 9 February 1986) is the youngest daughter of King Hussein of Jordan and Queen Noor.  She has two brothers Hamzah and Hashem and an elder sister Princess Iman.  She is a half-sister to King Abdullah II of Jordan.

Princess Alia bint Hussein: Princess Alia bint Hussein (born 13 February 1956) is the eldest child of King Hussein of Jordan from his first wife, Sharifa Dina bint Abdul-Hamid.

Haya bint Hussein: Princess Haya bint Hussein (Arabic: الأميرة هيا بنت الحسين‎ ‎ ; born 3 May 1974) is the daughter of King Hussein of Jordan and his third wife, Queen Alia, and the half-sister of King Abdullah II.  Princess Haya is the fourth and junior wife of the United Arab Emirates' prime minister, Sheikh Mohammed bin Rashid Al Maktoum, being known internationally as Princess Haya of Jordan.  She is a 41st-generation direct descendant of Muhammad since she was born to the Hashemite family (who have ruled Jordan since 1921).

Prince Omar bin Faisal: Prince Omar bin Faisal of Jordan (born 22 October 1993) is the second child and elder son of Prince Faisal bin Hussein and Princess Alia and is a nephew of King Abdullah II of Jordan.  He is the younger brother of Princess Ayah, and older brother to the twins Princess Aisha and Princess Sara.

Supporting paragraphs: Princess Aisha bint Hussein Abdullah II of Jordan
Answer: 1999