Complex sentence: Their association lasted until 1982, when due to ego issues both decided to split after which Javed moved into writing lyrics for around 80 films and scripts for 20 films from 1981 till present times whereas Salim wrote for 10 scripts between 1983-1996.
Split into simpler sentences: Their association lasted until 1982, when due to ego issues both decided to split. After which Javed moved into writing lyrics for around 80 films and scripts for 20 films whereas Salim wrote for 10 scripts between 1983-1996.