The 16th Lok Sabha elections, associated with many firsts for the country, would be held from April 7 to May 12. The counting of votes for all the 543 Lok Sabha constituencies will be held on May 16. The 2009 Lok Sabha polls, incidentally, were held in five phases from April 16 to May 13. An estimated 814 million voters will be eligible to vote in the coming elections. The firsts include: * None of the Above (NOTA) option in voting. * A system of paper trail for electronic voting to be introduced in some constituencies on a trial basis. * Candidates in a Parliamentary constituency in bigger states can spend up to Rs 70 lakh, up from Rs 40 lakh in 2011. The limit was Rs 25 lakh for the 2009 Lok Sabha elections. The nine-phase schedule is as follows: Six constituencies will go to the polls on April 7. Seven constituencies will vote in the second phase on April 9. 92 constituencies will vote on April 10. 5 constituencies will vote on April 12. 122 constituencies will vote on April 17. 117 constituencies will vote on April 24. 89 constituencies will vote on April 30. 64 constituencies will vote on May 7; and 41 constituencies will vote on May 12.