The unicameral parliament initially had 270 members, but increased to 290 in 2000. Another increase is expected for the 2012 election. Deputies represent 207 districts. Five seats are allocated to religious minorities: two Christian Armenians, one Assyrian-Chaldean Christian, one Jew and one Zoroastrian. Districts with large populations have multiple seats. All eight parliaments have had female members. The largest and most important district is Tehran, which has 30 seats. The original voting age was 15. But in 2008 the voting age was raised to 18, and the minimum age for deputies is now 30.
One of the most notable trends has been the decreasing participation of clerics in the legislative process. The first parliament had 131 clerics, and the second parliament had 148 clerics. The sixth parliament, elected in 2000 and dominated by reformists, had only 35 clerics, the lowest number to date. In 2008, 42 clerics were elected to the eighth parliament, which was dominated by hardliners and conservatives.
The second notable trend is that the decline in the number of clerics has coincided with a rise in the number of deputies with backgrounds in the Islamic Revolutionary Guard Corps (IRGC). But the growing IRGC presence in parliament is still far from the clerical dominance of the 1980s.

