Days from the ex-dividend date to the pay date, past two years

SELECT
    multiIf(gap_days <= 7,  '0 to 7 days',
            gap_days <= 14, '8 to 14 days',
            gap_days <= 21, '15 to 21 days',
            gap_days <= 28, '22 to 28 days',
            gap_days <= 42, '29 to 42 days',
                            'More than 42 days') AS ex_to_pay_gap,
    count()                                      AS declarations,
    countDistinct(ticker)                        AS securities
FROM
(
    SELECT
        ticker,
        ex_dividend_date,
        dateDiff('day', ex_dividend_date, any(pay_date)) AS gap_days
    FROM global_markets.stocks_dividends
    WHERE ex_dividend_date >= today() - 730
      AND ex_dividend_date <= today()
      AND pay_date >= ex_dividend_date
      AND pay_date <= ex_dividend_date + 180
    GROUP BY ticker, ex_dividend_date
)
GROUP BY ex_to_pay_gap
ORDER BY min(gap_days)