Which of the following statements is incorrect about India and Pakistan's exchange list of nuclear installations which was recently in news in the month of January 2011?

Under the agreement signed on December 31, 1988, the two countries share details of their nuclear installations with each other on the first day of every year.

The first list was exchanged on January 1, 1991.

The agreement came into force in January 1991.

On 01-01-2011, India and Pakistan exchanged the lists of their nuclear installations for the 20^th consecutive year under an agreement which prohibits any kind of attack on such facilities.